Don't know about you, but I hate vanilla.
Why do you hate vanilla so much?
It's so boring, plus it's so mainstream.
It's perfectly fine to not like vanilla. Everyone has their own personal likes and dislikes when it comes to food, so as long as you don't push your tastes on others, there's nothing wrong with it.
I don't actually hate the flavor of  vanilla itself, I hate it for being so mainstream and I'm sick of seeing it everywhere.
It's OK to eschew mainstream tastes, as long as you aren't a snob about it; you should be careful about making generalizations. Some mainstream foods can be decadently fun, like vanilla sundaes with caramel sauce, bananas, whipped cream and walnuts. Did I mention the cherry on top?