Nothing, unless you read a lot of Anthony Bourdain. He's abrasive about a lot of things. Also does a TV show called "No Reservations" that I think we discussed briefly on another page recently, but no idea which one.
I'm not about to start the Butter Wars, but my point is that any chef works within certain limitations ... available ingredients, seasonality, staff, time, size of kitchen, etc. If the particular constraints happen to be those of vegetarians or vegans, why are they any more of an 'irritant' than the usual drum?
What irks me is not so much the implied slur on vegans (AK 47-toting militants? stand back or I'll fire a bunch of rocket salad across the Israel border) because that's so fucking silly it's headed straight for the worm farm. More, it's the sheer snobbishness of Anty Brain, bubbling forth like the hissy-spatter of fried soy-giblets; heaven forbid that chefs should serve the needs and wishes of their customers! No, the customers can go rot in their orange jumpsuits while it is the chef's prerogative to assault their palates as he/she pleases. I disagree and I disagree.
Being debarred from butter would seriously compromise, say, a French chef's aims; everything depends on the culinary tradition. Not all cuisines are equally well adapted to vegetarianism. 'Making something' is hardly superb cheffing, to borrow a Woosterism.
That said, there is an abundance of splendid vegetarian chefs, and it's crude of TB to dismiss a sub-continent altogether, given his supposed cosmopolitanism. Then again, he's a crude dude.