Ok, so since you still don't get what I'm saying. Let me ask you this. Why do you expect as much buildup for a character that is left mysterious and ambiguous at first glance and through the episode

She wasn't left mysterious and ambiguous. She was pretty clearly stated to be bad, a shatterer, and the leader of all the gems in there. I don't understand how you can't get that through your head. Sure, we didn't see more of her personality or obviously her grief from Pink's supposed demise since Pink was still around, but that doesn't mean she wasn't revealed.

The Answer was her first appearance

Finally you got something right!

it's clear the writers weren't ready for a full debut yet.

Again. Just because Steven's Dream shows her in a BETTER way DOESN'T MEAN IT'S HER DEBUT! If a singer decides to finally hold a concert, and is mainly ignored that time, and then they hold a second concert with much better songs and become famous because of it and get to really show their abilities, which was the debut? THE FIRST ONE. Not the second one, except for fans who have it in their heads that since the second one was better and had more time to practice, then it's their "real debut". It doesn't matter if the writers were ready or not, THAT WAS BLUE'S DEBUT.

You clearly don't understand how writing works, and it's honestly insulting.

Because I'm being critical in a "Controversial opinion thread"? Clearly it is you who doesn't understand that the Crewniverse's writing can be BAD. It's insulting to all works that you just assume the good part of their writing is the only one that counts, because writers can MAKE BAD DECISIONS.