I could not disagree more!
What you are saying is there is some "Conspiracy at Microsoft" to distribute malicious files marked as "Updates" that will corrupt the Windows XP Operating System and force those users to switch to Windows 7 and so increase Microsoft's profits.
Frankly? I have never heard such a strange idea.
You say you have been around computers for over 3 decades. During that time therefore you will have seen the countless legal actions taken by governments and states against Microsoft over anti-trust and other matters, and yet never once has their been any indication of conspiracy to cause OS corruption in favor of newer products.
You say that you have seen so many semi-dysfunctional XP updates over the past months, yet no details and no specifics. I can tell you, as a voluntary (unpaid) member of the CNET team and a constant and consistent user of Windows XP since it was released in 2001 that none of the updates issued by Microsoft for my machine has caused what you are claiming,and my system is fully up to date.
What you do not state is the condition of these systems you say you are aware of and, presumably, inspected, and the knowledge of the users who have these systems.
If you would care to browse through the many thousands of posts and discussions in these forms, you might find a continuous running theme in them that would tell you the following;
1] User intervention. Windows is by and large completely customizable. Users can add whatever 3rd party software they wish, from whatever sources they wish, to customize their OS as they decide. Microsoft has no control over the software that users decide to install and this is one of the great strengths and weaknesses of the OS. Unlike Apple where the Apple Corporation maintain a tight grip on what can or cannot be installed on their systems, Microsoft allows the user a free hand. Simply put, if the software developer fails to write the code properly, either because they are inadequate or because they simply cannot be bothered, then at some stage that software may cause problems.
Users make the decision to install software and if that software causes problems the users then often blame Microsoft.
2] Malware. Because of Microsoft's comparably "Open Source" policy, Windows is the OS of choice for the majority of malware writers. You will know in your 35 years of knowledge and expertise how the fairly recent phenomenon of malware can destroy an OS in seconds, or can cause damage so deep that it affects the OS in many different ways. Indeed there is much malware out there that actively attempts to prevent the user from installing updates which might close the vulnerabilities that the malware writer is taking advantage of to gain access to a computer.
It can be safely said that all malware is installed by the user either by bad practice or lack of knowledge.
3] You mention how updates make XP slower and more crippled. You make a good point in that the OS does slow down over time. It is bound to. But updates are only marginal in that compared to the 65 million lines of code that a stock install of XP contains. All systems get slower over time, not because of updates but because the user does not 'maintain' their system properly. They allow software to install "Run at Startup", or set Services and Processes to run that soak up memory that is needed elsewhere. My system is now nearly 10 years old and it is slower than when I first purchased it. But that is not the basic OS. That is because I have been continuously installing software over the years and I want that software to be available immediately I boot up. I am aware of this and accept it, and I also take particular care of this OS because I am aware of its age, and I am aware that newer software demands more from an OS and from hardware.
There will be many others here who will give you plenty of other examples why your contention is incorrect. Your contention and complaint, accusation and allegation is incorrect.
I've seen so many semi-dysfunctional XP updates over the past months -- including one that TOTALLY hosed one computer and required a complete restore from an earlier date -- that I want to raise the Q of whether it's time to stop adding any more XP updates.
The bottom line/sad fact is that Microsoft has powerful financial motivations to drive as many people as possible, to Windows 7. So, what better way to do that, than to begin a gradual process of assigning less and less skilled programmers, to prepare updates for the no-longer-wanted old version? As more and more not-so-good updates make XP slower and more crippled, more and more people will simply give up, and buy the newer version.
BTW, I'm an engineer and patent attorney, working with computers more than 35 years. And I've seen how companies really and truly are driven by profit motives and profit margins, rather than any sentimental desires to keep customers happy, or to keep older systems running when new ones make more profits.