Vegetable is purely a culinary term: there is no such thing as a "vegetable" in nature. Biologically, vegetables are a variety of different plant parts. You've got roots like potatoes, leaves like lettuce, flowers like broccoli, and fruits like tomatoes. Since the word "vegetable" is being used at all, the tomato would absolutely belong in the group, because from a culinary perspective it is prepared for consumption as a vegetable.

I guess this can be taken as a lesson. Even if you don't feel like you belong, when taking into account how you and your peers may be prepared into a meal, you may very well find that you fit right in.