That is the view of former title-winning Benetton and Renault team boss Flavio Briatore.
Ferrari’s Vettel is being roundly criticised for mistakes that, despite earlier having the better car, have dropped him far behind championship rival Lewis Hamilton.
Mercedes’ Hamilton defended him.
“I feel the media need to show a little more respect for Sebastian,” he wrote on social media. “You simply cannot imagine how hard it is to do what we do at our level.”
But Italian Briatore agrees with those who think Vettel threw the title away.
“He will finish second, and it’s always a fine line between the winner and the first loser,” he told Bild newspaper. “I think Sebastian made a lot of mistakes this year.
“He must learn that a race is 53 laps, not just one. You don’t have to win every race to be world champion, you have to keep scoring.
“Vettel races for race wins, and that’s not how it works.”
Briatore acknowledged, however, that Ferrari also “made a lot of strategy mistakes in the last three or four races”.
Ross Brawn, who is Liberty Media’s F1 sporting boss but arguably more famous for his earlier role at Ferrari, praised the Italian team for catching up with Mercedes this year.
He said: “There is no doubt that the sudden death of Sergio Marchionne had huge consequences. He was such an important figure within the team.”
Brawn said he has lived through plenty of Ferrari crises, explaining: “That’s why I know it’s now time to put heads together, stay united and look ahead without blaming one another.
“An unwritten rule in every sport, not just formula one, is that the drivers, engineers and management all win and lose together.
“Everyone at Maranello knows that too,” he is quoted by Speed Week.