>>49811784First: I do not feel as if the Vanillite line is bad because it's too simple. There are plenty of Pokemon where that is a problem, Vanillite is not one. If it was more complicated, it would be worse.
Second: Being cute is, far and away, the most common trait a Pokemon can have up to this point. Just being cute is a really tough sell, because you're going to be compared to every cute Pokemon ever. I'd argue that cute is probably the most common design trend if you took every single Pokemon and count up the goals, so if "just be cute" is a Pokemon's strategy, it better be really really cute (Vanillite is not, it is simply just average cute).
Third: Edible Pokemon has never sat right with me in general, because being food is the last thing any organism should strive to be. In addition, Ice Cream is as far from nature as you can get, on an element that is more natural than most. That aspect of human influence breaks the immersion of Vanillite as a real animal that exists, without really bringing any more intrigue to it. Humanity has not shaped this Pokemon, it just exists that way.
Fourth: Trubbish is a great Pokemon design for the same reason Geodude is. It's Garbador that sucks.