I've never been convinced by Perez.
He had 4 good performances in his 2 seasons that I can remember. His debut, and then the three podiums. You can argue that his podiums were more strategy based than actual pace. I've found him to be lacklustre, and hot headed. I don't think he's even scored back to back points finishes.
Kobayashi finished 6 points behind him with more misfortunes, yet he's out of F1, and Perez is at a top team.
He's still too raw, although the car doesn't help matters, he could go as the same route as Kovalainen if he isn't careful.
Add to that, Ferrari were right not to replace Massa with Perez.