Bourdain and his production company had a hand in launching Lucky Peach, popularizing Food Republic and producing Mind of a Chef. He put a spotlight on David Chang and helped turn the Momofuku empire into what it is today. He's the reason people that are into food but have never set foot inside a Michelin-starred restaurant have heard of Noma. His endorsement on the back of a cookbook "legitimizes" it. Hell, he's probably the reason White Heat saw a big, fancy rerelease last year.
Though I like Bourdain I agree that he's a bit of a bitch, but to pretend he's not hugely important is ignorant at best.