Marko, speaking to The Red Bulletin magazine believes those criticisms of Vettel are unjustified.
"There is a lot of nonsense being said. “Vettel can’t overtake.” Ridiculous; just look at Abu Dhabi and Brazil. “He is only able to win because he’s sitting in a Newey car.” We have two Newey cars, so why aren’t we clinching one-two at every race?"
Marko also criticised triple champion Sir Jackie Stewart.
"Then the comment of the great Jackie Stewart that Vettel must go to another team to prove himself. This is said by someone who scored all his greatest successes in just one team, Tyrrell. I can’t take it seriously. We at Red Bull Racing are not just a bunch of civil servants. As long as we provide Sebastian with a car and an environment in which he can become world champion, he will probably stay with us. If both do not fit, then we have to come up with something fresh. But we have a very good junior programme, and maybe some day someone else will become champion in our car."
Marko also believes Vettel had a strong 2012 season.
"Sebastian’s driving was virtually flawless. But he is a phenomenon: it is always like that. After the summer break, his performance curve shoots up. That’s what happened in previous years, too. I don’t know how he does it, but to keep doing it cannot be a coincidence".
"That brings us back to his method of preparation, the way he shuts himself off from the rest of the world, so that he can still call on reserves that other drivers might not have: Fernando Alonso, for example, who is busy with politics and funny comments. Vettel ignores it all, he doesn’t read the newspapers, or the internet. And that’s the point, you see, we concentrate on our job: to make the fastest car and the best team possible".
He also added that Mark Webber has some races were he is unbeatable, but cannot sustain a challenge throughout a season.
"It seems to me that Webber has on average two races per year where he is unbeatable, but he can’t maintain this form throughout the year. And as soon as his prospects start to look good in the world championship, he has a little trouble with the pressure that this creates. In comparison with Seb’s rising form, it seems to me that Mark’s form somehow flattens out."
"Then, if some technical mishap occurs, like with the alternator for example, he falls relatively easily into a downward spiral. No driver remains unaffected by this, because the tension is palpable. In 2010, it was particularly extreme. Webber headed into the final race with better chances than Vettel, and he probably carried the disappointment of his defeat into the 2011 season, which is so easy to understand".
Marko says he understands why Webber sometimes struggles against Vettel.
"Something that I think is also very important is that for much of his career, Mark was never in a top team, but he was always regarded as a high flyer if he only could get into the right team. Then Red Bull puts him in a car – a possible winner – and suddenly along comes this young kid and he snatches the booty from under Mark’s nose. Psychologically it’s not easy, of course; this would gnaw away at anyone’s confidence. It’s more than understandable."