I think you’re forgetting how good he was at Dortmund.
He had one good season. He was pretty shite under Klopp, who's one of the best attacking managers around. His performances have more to do with his mentality than tactics or his ability.
He simply doesn't have the required mentality to make it at a top club. He doesn't seem the type of character to thrive under pressure which is what's needed at clubs going for major honors.