Legit. My dm in middle school let me make a character with a custom species, and it was more than a little unbalanced (because I was in middle school and thought victory was the only thing you played for). After two sessions we gave the character an ignominious death and I brought in something out of an official sourcebook.

Half of the fun in TTRPGs is fucking up and having to figure out a way around it. Take all of the risk out of the die roll and you might as well not roll at all. Use a different system.