StingingVelvet: Yes, but there are definitely genres that need a controller and to say "KBM or don't release it on PC" just means less games on the PC. Street Fighter, racing games, platformers, etc. I like those games and enjoy playing them on the PC in higher resolutions and such.
Antaniserse: Let's not forget the ever loved Tie Fighter, which despite beiing a PC only title, couldn't actually be played at all without a joystick
First, if you actually read the thread, you'd see that it was possible to play it with keyboard&mouse. People here did, anyway.
Second, the joystick is as much a PC controller as the mouse. It's been there longer and it's always been the best option for flight sims, among others. On my first computer (an Atari ST), I had both a mouse and a joystick and about 50% of games were best played with one, the rest with the other. When my brother started playing on an Apple II, though, he only had a joystick, no mouse IIRC. Guess what? It was still a computer, not a console.