Wow that is some amazingly bad info, but points for the BOFH reference.
1: Apple systems really are not that overpriced compared to PCs. Some of the things that make Macs seem more expensive is they have high end video cards and expensive DDR3 RAM, whereas most PCs still only come with DDR2 RAM. Apple also doesn't tend to do low end like say HP and Acer do. Apple also uses more expensive aluminum for most of their system cases, as opposed to cheap plastic for most PC cases. You go to a Fry's or anywhere else, and look at the Aluminum cases compared to the plastic, and they will have a premium price tag attached. And try to find an LCD panel out there with LED backlighting like is used in the iMac and MacBook/MacBook Pro then compare prices.
2: You can get parts on eBay pretty easily if you know what you're looking for, and there are plenty of guides out there for taking different systems apart. Systems like the iMac take a little prep work, and you need to be careful if you don't know what you're doing, but the same could really be said of PCs. I learned the hard way not to forget screw standoffs for a motherboard some years back. If you rush in, and don't plan ahead, PC or Mac, trouble awaits you.
3: It's actually based on FreeBSD, something of a cousin to Linux, but unlike Linux, is actually a (BSD) Unix descendant. That last bit really only matters to people with way too much time on their hands, but at one point Apple had I think 10.5 certified as an official Unix. And the GUI is based in large part on NeXTStep, and implements the OpenStep API, and has added a lot more since then.
4: This is against the license agreement, and is really a lot more trouble than it's worth if you ever look into what all is involved.
5: While I generally agree, function trumps form, until the iMac came along, computers were pretty much nothing but blocky beige boxes. In the years since the introduction of the iMac... Those now ugly seeming CRT all-in-one systems... You've seen a veritable explosion of design choices for computers. Clearly Apple tapped into a dormant desire of people or we'd still have beige boxes for everything. Amusingly, Apple has gone back to a sort of beige with their aluminum unibody cases, and they changed their logo from the rainbow fruit to a simple black apple.
6: No they haven't. Maybe all the big name apps like Photoshop, but there are plenty of great OS X specific apps. I don't use it myself, but Final Cut Pro is supposed to be something of the standard setter when it comes to high end video editing, and it's made by Apple, so it's OS X only. Just as one example.
7: Depends... The Mac Pro is generally a true joy to work with. That case is a work of art IMO. Everything is modular, all the cables are neatly tucked away, independently controlled fans in three distinct zones so you maximize cooling to the parts that need it while keeping fan noise at a minimum... In earlier models the RAM was installed on trays that just pulled right out, now the RAM and CPUs are on a specific tray which just pulls right out, making access incredibly easy. Just pull it out, set it down on a table, and you don't have to worry about bashing your knuckles into anything or tight cramped spaces around the memory banks. But Mac OS X has a number of interesting software engineering aspects which means performance tends to stay considerably better for longer. The process scheduler in Mac OS X 10.6 is generally heads and shoulders above anything else in the PC world. You'd probably have to go to mainframe systems to find something better. Linux developers probably deserve a lot of credit for trying out a bunch of different ideas the past few years, and giving the OS X developers some idea of what works and what doesn't, but Grand Central Dispatch really is a very well thought out bit of software engineering.
8: No, it's FreeBSD, as I said above. But I'm failing to understand how this is a bad thing. They took a solid OS, with around 30 years worth of development experience behind it, and then decided to build on top of that. Where is the bad part in all of that?
Now, there's a lot to be said about Apple the company, and their annoying "I know what's best for you" nannying, but that's largely confined to iOS devices. And iTunes, IMO, is a steaming pile of dung, but it's killed off virtually any serious competition for music playing software on OS X, even Windows. And if you go into an Apple store, you swear at any minute you're going to see an employee popping another Prozac because they are so annoyingly cheerful.
But allow me to offer some perspective. I work as an ACMT. My job, is to fix Apple systems. I also have fixed Dell systems in the past, and currently tinker with Toshiba laptops when I don't have enough Apple systems coming in to keep me busy. I held Dell's Warranty Parts Direct (now Dell Online Self-Dispatch) certification for over a year, and Apple certification for close to 2 years now. Toshiba doesn't really have a certification program, they just expect people to be A+ certified, which I've also looked into.
If you compare the certification process of Dell and Apple, and even A+, the others are a joke compared to Apple's. Apple's certification material, printed out, sits about a foot high off the ground. It covers both their hardware AND their OS, which is something all other certification programs leave out, but is very important. You can't be a good hardware tech if you don't know enough about software to be able to tell which one is causing the problem.
Dell's certification was a joke. The whole thing was essentially open book, you take it online, and getting recertified basically meant just paying annual dues to Dell. Until recently A+ certification, which basically amounts to a bunch of "best practices" garbage, was good for your entire lifetime. You could be certified 10 years ago, and it would be still valid. Now they've changed that to something like 3 years I think, but if you look at the A+ material, it's a joke. If you can't pass that, you have no business even thinking about fixing computers.
Apple requires you go through material covering every system that is still in service. Apple stocks parts for systems up to 5 years, then they hit Vintage status where only systems bought in CA can get parts, due to CA state laws. After 7 years, systems go into Obsolete status and they destroy any remaining parts. So even though Apple had long since shifted to Intel, I still had to learn about a number of their PPC systems.
Tests have to be taken at Prometric testing centers, you can't take anything in with you, and you have to get pretty high scores to pass. There are also two sections on technician safety and ESD, which you MUST get 100% on or you fail the entire rest of the test, even if you get every other question right.
To renew your certification, it's an open book, online test, but the questions get considerably more specific. Like, if you have a Late-2009 MacBook Pro, what screwdriver head do you use to remove this part.
Apple's was the first certification I've obtained, or even looked at, where I felt like the material was actually pretty comprehensive and prepared me for the task of fixing systems. Most certification programs are book selling scams, money making scams, and exist so that managers in companies don't have to actually learn anything about the subject for which they're hiring someone. Which is really kind of stupid when you think about it. However, the comprehensiveness of Apple's certification actually managed to impress me. And there are plenty of valid gripes one can have about Apple, but not when it comes to their computer hardware and software. I can't speak for the iPhone, iPod, iPad, AppleTV, or whatever else they may come up with, but their desktop and laptop computers are first rate bits of hardware, and OS X is quite probably the single best desktop OS that exists today. All of which may be subject to change in the future, but right now, it stands.