Like today's computer scientists, early biologists sucked at inventing new words, and simply reused existing ones. "Berry" in common language is a small, usually sweet and edible, fruit. Strawberries, blueberries, blackberries and raspberries are all berries.

Then biologists came along and decided, actually, strawberries, raspberries and blackberries are out, but watermelon and bananas are in, because the size of the fruit doesn't matter, only the placement of the seeds decides whether something is a proper, scientific berry.

A similar thing has happened with "fruit" and "vegetable", where scientific fruits include cucumbers, eggplants, and pumpkins. Luckily, all three of these are also berries.

I say we ignore them, and use words to mean sensible things.