Quote Originally Posted by Beckett View Post
The full idiom is literally, "You can't fit a square peg in a round hole."

I definitely disagree with calling a BLU a square peg that can't fit into the round hole of XIV's group content, but I'm sorry, you're just straight up wrong about the meaning of the phrase.
No. That's how people modify it, it's not the idiom. The idiom is literally just 'square peg in a round hole', alternatively 'round peg in a square hole'. It is used specifically for people.

Dictionary.com
Collins
Wikipedia
Merriam

Idioms are specific. If you add stuff to them, they stop being idioms. Sure, some people do say "you can't fit a square peg in a round hole", but as I said, it is the modern interpretation of people too ignorant of the actual meaning behind the idiom they try to use. And unlike is the case with definitions of words, idioms cannot evolve. Only be forgotten and new ones made.