The reason for this is that they are closer to the edge of the envelope and there is less margin for error. Vettel is able to get right to the edge of the envelope and make no mistakes. And he seems to do this in almost all the races.
I would argue that Vettel has very very rarely put that car on the edge during the race. And on at least one occasion when he did put it right on the edge because he was getting caught he binned it.
Hamilton, Button, Alonso and Webber are all having to put their car on the edge far more often because of a slower car or lack of ability in the same car.
Vettel is a good driver. He is a great 1 lap specialist and he is fantastic at leading from the front in a car faster than everyone elses save for his team mate who, everyone agrees, isn't a patch on Vettel, Hamilton or Alonso.
In all honesty I don't know how you can say much more than that after 2 years of utter dominance. Had MSc been in a dominant car at that age then he would have won more, of that I have no doubt.
I honestly think that if you had Alonso, Hamilton and Vettel in the same car with no driver being favoured over another, Vettel would come third on points over a season out of the three. I wouldn't want to pick 1st and 2nd.
At the end of the day it's not Vettels fault that his car is better than his competition and I like the guy as a person unlike some who for some reason hate him. He just goes out there and does his job. But to wax lyrical about how fantastic he is when the reality is that he hasn't had a title challenger in the 2 years he has won the title (because lets be honest, this years is his) is going over the top.
I know you are convinced you are right and that everyone else is wrong. And I know that the pundits and stuff are saying he is the second coming. But we are all entitled to our opinions and we can only judge on what we have seen and what we know. We don't know Vettel like DC does, but we are also allowed to voice our full opinions a little more freely than the pundits who would be met with scorn and anger if they said anything other than "he has won by a million points and I want his babies".
I'd love to see Hamilton or Alonso into he same team as Vettel. If he could beat them in the same car then fair play to him, he is a fantastic driver worthy of the title. All the time he is playing with a stacked deck however I find it difficult to ever get excited by anything he does outside of Qualifying.
And thats the bottom line, because Todge says so