Well regardless of how (un)hackable the ps3 is, the numbers don't lie, 360 in terms of sales is superior to the ps3 and ps3 fans are notorious for their varying taste in games whereas 360 fans are more predictable, if you cater to to the garunteed individuals, you're more likely to get more for your money especially when you consider the 360 is easier to build for.
Less work+ more returns= win.
Is the basic gist of it.