Everyone else's software/hardware is just that bad, so Apple can fuck around for years and switching's still a tough sell. That's why I'm still around, anyway. This WWDC looks like a move in the right direction for the first time in a while, at least.
Because we as developers also desperately want a UNIX-style system, and our lives are so much easier when we can choose one that won't get us laughed out of the room by commercial software vendors.
Because I can fully customise it using something like BetterTouchTool.
And so in IntelliJ I have custom buttons for executing common commands. I never remembered what each function key does in each app so it's useful for me.