Even as someone who enjoys "retro tech" far more than anything modern anymore, I'm hardly going to berate people to bend over backwards to keep supporting my ancient systems with modern software.
If someone wants to backport newer software as a hobby (such as Cameron Kaiser with TenFourFox, and the many downstream derivatives that spawned over the years) it's a welcome delight. But it should never be an "obligation"
Perhaps that'd be the OpenRCT2 fanatics' salvation.
The only reasons to keep Windows 7 are for niche SW/HW that only work on it and have no replacement, or because you want it out of principle. Neither of these are reasons to expect everyone else to bend over backwards to accommodate you.
Those "security reasons" start more and more to look like "think of the children". The biggest entry point for exploits nowadays is the web browser, yet nobody cares about it (just look at the list of CVEs fixed at every browser release).
You might say, well the stories aren't there because of how many people upgrade their OS's nowadays, but apparently enough people are on Windows 7 to make a stink (rudely, unfortunately) when Dolphin dropped Windows 7 support. And we all know how bad the Android OS upgrade situation is.