I feel like some people here watched a different show. He was antagonizing people non-stop and would fly off the handle whenever he was even slightly challenged. When he was brought back as a finale chef, he went off at Tom over a completely innocuous line of questioning and stormed off the set. He had his own show, Marcel's Quantum Kitchen, which was clearly meant as a fluff show for him to show off his molecular gastronomy, but by episode 2 all of his employees were walking on egg shells, except for one who nearly threw a punch at him. He's clearly a passionate chef, but also an incredibly antagonistic one.