Some people use the term vanilla pejoratively, in reference to something bland.
And of course, Gumby-haired Vanilla Ice ruined it for all of us 'nilla mavens. Personally, I like vanilla, especially in ice cream form. It's a fine flavor on its own, and even without accoutrements such as nuts and hot sauces, it's a satisfying dessert. It may lack the complexity of a convoluted, overwrought, multilayered deal, but for all those nights of watching Walker, Texas Ranger in sweatpants and no makeup, give me a pint of plain ol' Haagen-Dazs any day. We can't find anyone who wholly dislikes it.