I think, considering Magnussen is a rookie at McLaren, unlike Perez who was in his 3rd season, he is doing okay. I wanted him be betyter myself. Starting with a podium in Australia has not made the season any easier. Magnussen is still adapting and he is seeing the majority of tracks for the first time. Would continuity not be better than starting from scratch with a new driver and engine in 2015. People also compares Magnussen's rookie season with Lewis', which is fair, but to be completely fair Lewis' debute was in car that was one of the best if not the best. Magnussen is in a car that does not deliver as expected and he is probably more prone to overdrive the car to compensate for the cars lack of speed, there by making more mistakes. I hope Magnussen stay on, F1 might eventually colapse on it self if rookies are not "allowed" to be rookies and at some point a new generation must take over. We do not want rookies to just strickly buy their way into F1.
I find the *rookie* card to be a bit of a ploy really as after their rookie season is over, they then become a 'young' driver and this is only because it seems F1 drivers these days are getting younger and younger and i don't think it's fair to play on such emotion just because of the season and the car. Perez may be in his 4th year now but in reality, he's only 24, that's rather young. I don't think it helps when names like Sebastian Vettel and Lewis Hamilton goes and wins championships at such a young age when although they may be good, it can be because of the car. If they decide to drop Magnussen after his 'rookie' year just because the car is still not performing then i think they are lacking simple common sense and the idea of sport. Yes, winning is important but these are people's young lives, and every car no matter what is what will drive them forward (no pun intended) in their career, if the car sucks, who cares, give them the time they deserve and one day you may just get a winning combination; just like Ricciardo and Rosberg.
As for other drivers who lose out because of one thing or another, i think it's unfair when the driver hasn't been able to have their 'time'. Out of the entire grid the only drivers (That could go) i wouldn't feel sorry to see go are Sutil and Button. Button has won his championship and has become one of Britain most iconic racing drivers and Sutil well..
Ericsson, Kobayashi, Gutierrez, Chilton, Bianchi, they all deserve a chance to prove themselves for longer than a few years in bad cars (Or in Kamui's case, not getting shafted because of money woe's)
Then of course we have drivers like Pastor Maldonado whom i actually like, i really do, but he needs help. Whatever they did to Grosjean, they need to do to him. Swiftly segwaying into Grosjean by that chance, i worry for his future also. An amazing talented driver right now stuck in a dying team. Mercedes, Ferrari, RedBull; None of these 3 teams will be changing anytime soon so he's in trouble if they end up dissolving.