Microsoft didn't change the game. Mojang did, Mojang are still in control and are funded/owned by Microsoft.
The addition of another version on a different system doesn't alter the game. The windows 10 version doesn't impact the java version in any way.
Why is it weird that people over an age play a game? Many adults still do the things they did as a kid even if they are not aimed at older people, I still enjoy watching cartoons and I'm on the verge of hitting 40, it's called enjoying yourself.
Basically this thread is just you saying you have decided to game less and do other things. Good for you and enjoy what you like to do, like all the people who like to game will do.