At something like 6% of the world the market the population of ideological vegetarians and vegans is huge. With another handful of percent who are ideologically opposed to eating meat on certain days but not entirely vegetarian.
PS. Your claim that "most people are not ideologic with their food"... Not all food ideology is related to vegetarianism so it's not terribly relevant but I think this claim is just wrong. Islam + Hinduisim + Buddhism make up nearly half the world and all have pretty strong religious ideological beliefs about food, and a non-trivial fraction of the quarter of the world that is christian has at least a few scruples like avoiding meat during lent. And that's just people preaching religious beliefs not less documented ideologies like believing real men eat their steak raw or whatever.