Whereas what you are pointing out is that when issues are found, they are left unfixed in one of those OSes. That's a different thing.
[1] https://docs.microsoft.com/en-us/windows/threat-protection/o...
Windows 7 was released in 2009 and has received free support for years. In contrast, when did Ubuntu 9.04 (also released in 2009) lose security backports?
Perhaps Ubuntu 9.04 isn't a "fair" comparison, since most Ubuntu releases aren't designed for long support and the community recognizes this fact. But even then, the Ubuntu 10.04 LTS release (long-time support) was in 2010, and its support ended in 2015.
The mindset of "blame Microsoft" is quite annoying, when every darn Linux user is basically subjected to the "forced upgrade cycle" way faster.
Nobody forces gnu/linux users to upgrade. I know of happy CentOS 4 users; atleast they have the source to their os.
You are only forced to upgrade if you want the latest features and support for security fixes.
Microsoft is getting "blame" because it leaves you with binaries and a broken upgrade path.
[0]: https://en.wikipedia.org/wiki/CentOS#End-of-support_schedule
Two paragraphs later.
"what do you call it when Microsoft fixes security holes in Windows 10 that it doesn’t patch in Windows 7? I call it really, really stupid."
So Windows 7 has security holes that Windows 10 doesn't, but Windows 10 is no more secure than Windows 7. Right.