Fruit is a botanical term for things with seeds in it. Vegetable is a culinary term. They aren't mutually exclusive so when people say something is either a fruit OR a vegetable, it isn't an apples vs oranges comparison.
I mean, that it's a terrible definition of vegetable, considering it rules out a very large amount of vegetables, including tomatoes, bell peppers, eggplants and cucumbers.
You can apply that to pretty much any categorization we make for the natural world.
The natural world doesn't care for our categorizations or social construct. It can, and will, make shit that just does not fit to any of our boxes, and like it!
Ah yes, the semi-aquatic, egg-laying mammal of action. A key part of god's fight against those who demand everything be neatly categorized into simple boxes
Not nearly as much as you seem to think. "Anything can be anything" is a common line by people who don't know anything. "Autism is an infinite spectrum. Everyone's a little bit autistic!" "Everything that looks similar in some ways to a game that's been called an 'RPG' is an RPG!" Assumptions and infinite inclusions come more easily than actual knowledge and categorizations.
I was referring more to how there's an exception to every rule in, for example, biology (and other things in nature).
You mentioned autism, which by itself is an exception to the rule of how we think humans beings "should" be and act. And autistic people have long been tried to be forcefully put into the societally constructed boxes we made for ourselves, instead of accepting that some people are different and that it's ok.
Or how left handed people exist. Or how intersex is a thing. Or the myriad of medical conditions which, while not harmful, make people different, like situs inversus.
And that's just for humans. In nature you got everything from viruses which is debatable whether it can even be categorized as life, to platypuses, to fungi that have tens of thousands of different sexes. And this list is near endless.
It's a definition of "fruit": thing that's full of seeds, intended to fall off the plant.
Technically, any part of a plant is a "vegetable". Tomatoes? Vegetables. Lettuce leaves? Vegetables. Leek stalks? Vegetables. Spruce 2x4? Vegetables...
Why should anyone care this much though. It isn’t poisoning anyone. it’s not breaking anything in the kitchen. It’s still edible. No animal died to give it to you.just Eat it and be fed.
Generally when people talk fruits and vegetables they are referring to culinary tradition. Vegetable does not have a precise scientific definition anyway, despite what you've heard from The Big Bang Theory.