"I am annoyed when people correct me for using casual language. Doing so is stupid. Language isn't static. The purpose of language is to be understood, so as long as you understood me, I did it 'correctly'. Here is an analogy using plants."

That grammar evolves naturally, like species do, so any rules we find for the categorization of either should reflect reality, not try to dictate it.

For example, I just started that bit with a clause, which means it’s a fragment, not a sentence. I still put a period at the end of it and started it without any lead in, which is “wrong,” but it’s more that the rule is wrong, because what I wrote plays the role of a sentence in this case.

You can decide all clovers have 3 leafs. That doesn't mean 4 leaf covers stop existing or are wrong.

You can decide "but" is only for contradictions. That doesn't mean people won't use it other ways or it's wrong.

You can decide all men have penises. That doesn't mean some won't or that's wrong.

You deciding shit doesn't actually change reality. And being pissy about it is as idiotic as suing 4 leaf clovers for you thinking they should only have 3 leafs.