But you are not a developer. I am a developer.
No (read; very few) windows developers developed specifically for Vista until a few years after it was launched, because why give up 75%-50% of the market share?
Developers don't have unlimited resources, and they'd much rather develop for something that has a bigger market.

Of course, some will develop for Android or IOS, but those are different devices. If you develop for desktop, and you must invest money in the development, then you go for the mainstream. This is why there are so few Linux and OSX applications compared to windows.