This looks like a hasty port to counter holiday drought and gears of war onslaught.This is where Trophies come into play
They give an incentive to replay the game. I never managed to replay UC 1-3 but I will definitely try to plat this new trilogy.
Also I don't know about you but a MP game demands a lot of time. Those who don't have the luxury of having free time, like me, have zero interest in MP. I bought KZ, BF 4, Advanced Warfare and never managed to play much of their MP, because I was always busy in finishing another game and going back to them solely for MP is not my idea of spending the free time that I have.
Of course, there are also those who just buy 1-2 games each year and play their MP all day and night *cough* Destiny *cough*
With no MP, Sony is telling me that they dont value gamers money but want a stop gap solution until big release next year.
MS is evil, but atleast they are putting effort and commitment into remasters.