I'd say its more a case of, the only thing you can really say about Vettel, is he's better than Webber, he may be better than Alonso/Hamilton, but cruising around infront of everyone not really pushing the car doesn't prove that.
ULtimately Vettel can usually beat him in qualifying and has far less really bad qualifying sessions than Webber, and that makes a huge difference. Webber might be the second best driver on the grid, or the 10th best, or 20th, all we can say is Vettel is quite clearly outperforming him.
It seems like Webber tends to get more bad luck, more tyre issues and more kers issues, but ultimately when problem free he doesn't seem to have the pace.
i'm not sure Alonso has "outdriven" his car as much as people have said either, too much focus on qualifying pace and not enough on race pace, which Ferrari were solid in from the start of the season. I'm not sure Alonso deserves it because his driving has been spectacular, but he's done more exciting and difficult overtaking moves than Seb has this year, thinking ducking and diving in Valencia, ultimately Alonso got a 25 point gain on Seb because the Red Bull died than because Alonso drove brilliantly.
Ferrari have made mistakes but few and far between, one for the team(giving away second in Canada) and one from Alonso(turning into Kimi). I'm fairly sure I said not a few races ago that Ferrari will have some bad luck and ALonso will make a mistake, all drivers do.
You feel that Alonso has had more exciting drives and good races(compared to the cars ability) than Vettel has... but Vettel has needed to drive really hard less often.
Its not so much Vettel doesn't deserve it, its that he hasn't really proved it, because the car has been so good he's cruised to all his wins with no competition, and hasn't exactly blown everyone away when the car wasn't the best.
For me, no driver has had more points taken off him than Hamilton, his car hasn't had the margin say Vettel has had, when he has won, and no one else, full stop, has managed to finish races with as broken a car as he has in the past 3-4 races. The fishtailing drive, as Whitmarsh said, was the best point won ever for Mclaren, that car shouldn't have been capable of finishing let alone stealing a point or keeping anyone behind for as long as he managed.
Hamilton driver of the year so far for me, Alonso, put in the best drives of those in contention for the title, Vettel, might be great but hasn't really for 3 years had to prove it such is the dominance of Red bull's car.