I use it because:
I am poor, and it allows me to legally use software without paying for it, and use old hardware without suffering.
I enjoy the fact that people like you get so worked up about why I use software.
It gives me a lot of control.
It takes care of its self.
I don't have to worry about using cpu cycles to keep my web browsing from hosing my machine.
It's one of the few situations in life where I actually benefit from the investments of huge corporations.
Not in any way important to you. But there it is.