Sir, the programs on that list are built intentionally with Windows 7 compatibility in mind, so long as the compiler and engineering ingenuity allow, resisting artificial obsolescence. Because the original idea of a personal computer was to ease the burden of everyday people — people from the streets who are easy to forget about while sitting in an ivory tower with 32 GB of RAM.
I know about this simply because I walk among them and have been corresponding with these developers for years. Yes, there is another life out there — one different from the addict who needs a weekly dose of patches, and different from the hamster who needs a new wheel every year.
Listening to you, it sounds as if you’re breaking your back day and night, unloading heavy crates from a ship to a pier just to support every version of every OS. What is there to support when the changes between Windows 7 and Windows 10 are mostly cosmetic, and APIs are mostly renamed?
Complex applications like the 3D games BioShock or Deus Ex work great on Windows 7, yet your text editor — glyphs and spaces arranged on a canvas — is already choking. An OS does not die by a boardroom decree, but from a lack of demand — and there is enough demand for it.
Since you rely on Python for your development, just think about how to make this dependency more flexible. That way, a person on Windows 7 can grab a file from a backport (yes, the backport mentioned above, not some crooked, hacked, twisted bundle) and replace yours, bringing Sublime Text back to life.