You can mark me down as one of the "conspiracy theorists" in a recent Forbes article about Microsoft's latest service pack scandal. It is no secret that Microsoft has been doing everything in its power short of brute force to encourage users to upgrade their Windows 7 or later computers to Windows 10.
Put simply, Microsoft has decided that support for legacy operating systems is a pain (and expensive). Although the company promised to support Windows 7 until 2020, it is clear that Microsoft would rather not have to do so. At best, it will do a mediocre, careless, and inattentive job in providing support for Windows 7, Vista, and 8.1 (Microsoft has already stopped supporting 8.0, telling users that 8.1 is essentially a service pack for 8 that they must install for continued support).
Microsoft as the article link above points out, Microsoft has added an update to be downloaded automatically onto computers that it knows will render some computers inoperable. It simply has not bothered to fix this issue before adding to its recommended list. Sadly, Microsoft has a long history of pulling stunts like this to force people to upgrade.
For example when Windows XP first deployed in 2001, it ran well on 256 MB of RAM (1/4 GB). It could even run on half that, 128 MB. After several years and a service pack, the OS really seemed to require 512 MB (1/2 GB) to run optimally. But after Windows Vista and 7 came out, additional updates shot up that requirement to at least 1 GB. Today, running on less than 2 GB causes significant performance problems. Whether this was a deliberate change to convince users to get a new PC with the newer version of Windows, or just sloppy coding since Microsoft no longer cared about users with the older computers, the effect was the same. Technical people like me bought more memory, but most users just decided it was time to buy a new computer with a new version of Windows.
Another example, even though Microsoft goes through the trouble to make new security updates for Windows XP users even today, it does not make them available to the public. One would think that patching flaws and security holes would be expected. But Microsoft says no. Imagine if GM decided that problems that showed up in cars after 10 years were the driver's problem and that recalls or fixes to known problems were not longer required or available. They would not even notify drivers of these problems. I don't think that would go over very well.
In the IT world this sort of treatment is nothing new. Apple has ignored its old products and even sent out updates that destroyed them, like the iOS upgrade that destroyed the WiFi antenna in your iPhone 4.
Microsoft, you may argue, is at least giving away its upgrade. It is not reaching into our pockets and requiring us to spend more to be able to continue using our computers. But Windows 10 does do away with some functionality. Further, it allows Microsoft to get a great deal more information about how you are using your computer. In other words, Microsoft gets valuable marketing data about you. Microsoft also has not promised not to charge for Windows 10 updates in the future. Once you are moved to 10, it will be difficult and expensive to go back. If they start charging a year or two from now, you are stuck.
Other changes Microsoft is making to Windows 7 seems to be increasing the length of time it takes to start one's computer. Users are also seeing unusual lag times in other areas. These were not problems in prior years. Now, however, they are becoming much bigger issues. Since Microsoft has a direct financial interest in getting you to upgrade or buy a new computer, its hard to give the company any benefit of the doubt that fixing these problems is beyond its ability.