This I'm afraid is the price you have to pay for backing one horse over the other, folks who go for both get the best of both worlds but if you opt to be ps3 only then you have to make do with getting the short hand or nothing at all.
Point of interest, Bayonetta
This game was never meant to come to the ps3 but Sega went out of their way to make it.
On the one hand you could argue Sega just wanted the munniez but on the other hand, a ps3 only owner doesn't have a chance to play it unless they are thrown bones.
But then there's the question of games like FF13 and Tekken 6
Why settle for busting your gut to make a game for a console that has the least amount of owners only to get small change when you can port to a higher install and getting high(er) returns? When you are catering for a higher audience on an easier machine, folks are more inclined to work harder to maximise their product but if it's on a harder machine with lesser audience number...the insentive really isn't there to bust a gut.
So by being a ps3 only owner, you are signing up to inferior ports and suspect hand me downs, begs the question, would you rather play a shoddy version of your 3rd party favourites on your ps3 or not at all?