That's business, stop having so much emotional attachment to it.
Ah yes, the typical "It's just business so you better accept it" argument. Sorry, but no. Just because something is profitable for someone else doesn't mean I should accept or approve of it. Really, does Microsoft's profitability mean anything to PC gamers? Nope. As a gamer, I don't care about investors or profit margins. I care about PC games. When MS takes a game away from the PC, that pisses me off.
The better question is why hasn't anyone else stepped up?
Okay. You really don't seem to be getting the point here. This isn't a matter of stepping up. This is a matter of Microsoft actively hurting PC gaming.
Once again, here are the many ways in which Microsoft has hurt PC gaming:
1) Buying PC developers and having them make Xbox exclusives (Lionhead, Bungie).
2) Paying PC developers shitloads of money to make Xbox exclusives (Epic, Remedy, Bioware).
3) Taking games that were once PC games and turning them into Xbox exclusives (Halo, Gears of War, Alan Wake).
4) Buying and shutting down good PC studios (FASA, Digital Anvil, Ensemble, ACES).
5) Making DX10 a Vista exclusive.
7) Games for Windows Live.
9) Paying publishers a shitload of money to make 360-exclusive DLC (GTA4, TR:U).
Oh yeah, check this out. Looks like the PC version of Alan Wake stands a very good chance of not existing: http://www.shacknews.com/onearticle.x/59493