The first FF game I played was FFX and I was a bit young to play it at the time. I got part way through and then stopped for whatever reason. I began to have interest in FFXII but the time I became interested in it PS3 and 360 were out - no thanks I hate going back and playing PS2 stuff now, looks teh uglehs. So I wanted to see if I really like FF or not, so I rented FF XIII for 360. YES I have a PS3, but I prefer gaming on my 360 as the PS3 is used more often by others in my house to watch Bluray movies.
What's so wrong with having FF on multi-platforms? Personally I'm to chapter 6 of FFXIII and I really enjoy it. If it had been on PS3 it would've taken me far longer to get to this same point. If it was a crowd of PS3 fanboys then yeah, I could see part of their anger - Sony losing all their exclusives means less reason to buy a PS3 over a 360. Granted GoW III just came out and that's a hella exclusive, but Sony is running out and exclusives are slipping away. Sony still has Gran Turismo, MGS, and GoW (Uncharted if you want to include that but I'm with Yahtzee on that one) but GTA and FF were two other big franchises that always used to be theirs first - no more though.
From a fanboy perspective (I'm not, but I'm looking through how they probably see) this means when the next generation comes out, consider that the huge franchises like CoD and all that jazz are on both consoles - no real winner there. But the 360 has franchies that the masses love like Halo, Gears of War, Forza, Splinter Cell, etc. So Microsoft is racking up exclusives and Sony is losing them. So from an average persons standpoint, wouldn't you rather the console that has the most exclusvies you really want plus the big titles that they all get?
Me personally - I own a PS3 and 360 so I can play both exclusives (I'd only have a 360 if I had to go with the first one I bought, and I'd be killing to play GoW III...)! But others more strapped for cash don't have that choice. Still if it was a collection of FF fans what's it to them? The game isn't different other than you can - *GASP* - play the game on something other than a Sony game console! Everything about FFXIII feels just like it would on the Playstation.