PS4 lead architect Mark Cerny knew as far back as 2007 that "clearly we had some issues with PlayStation 3".
The system was complicated compared to PC and Xbox 360, and the result was PS3 often coming off worse during multi-platform game development.
End result overall the best looking exclusives with great gameplay. That cell churned out some beautiful games with the help of the best devs. this gen such as ND, SM and GG.
The PS3's architect was its greatest strength and its greatest weakness. It was a catch 22 situation. On one hand it produced some of the best looking console games this gen, on the other hand some of the multiplats suffered due to inexperienced developers (or just plain lazyness). It seems the PS4 will be tackling this problem head on and will be all the more better for it.
It wasnt a system that took 3rd party developers into account , it wasnt bad but it wasnt wise either , now with developers happy Sony will deliver the same high quality exclusives and the 3rd parties wont have to put a extra effort and money to develop for the ps4, they made it right and since Sony systems tend to be my 1st option the future looks bright!
The PS3 was an optimistic experiment. Luckily it didn't sink Sony. Sony had som good victories with it and the PS3 turned out ok. They've learnt their lesson.