Let's face it: Apple is every bit as proprietary as Microsoft. More so, in fact. Apple takes secrecy to new levels. It prefers to build everything itself and maintains a closed, tightly integrated ecosystem.
And yet many of us, myself included, regularly deride Microsoft, not Apple, for being proprietary and greedy.
Why does Apple get a free pass? Because Apple makes exceptional hardware and software that is consistently beautiful. Period. It's lock-in, but lock-in never looked so good.... :-)
I suspect that if the quality of Microsoft's products improved, we'd overlook many of its character flaws. I'm not talking about stability, in which area Microsoft has significantly improved. I'm talking aesthetics. Superior design covers a multitude of sins at Apple. At Microsoft, inferior design accentuates its multitude of sins (Monopoly past, Millennium, Blue Screen of Death, etc.).
Microsoft makes products that people have to use. Apple makes products that people want to use. That's why we love Apple and deride Microsoft. It's as simple as that.