I'm sure it can be done. I'm also sure that you could get some yam or even one of the sweeter varieties of squash in there if you really wanted to. But how often have you seen it done? And then think about how many standard main courses include tomato in some form.
Cucumbers, squash, zucchinis, pumpkins, peppers, eggplant, tomatillos, christophene, okra, breadfruit, avocado, green beans, lentils, snow peas, and soybeans could all technically be considered fruits too, but nobody really talks about them the same way....