>>2168146They can't merchandise Yui, and that doesn't really matter. Since when was a character defined by their merchandise?
What matters is what they are in the show.
For every Rei that isn't actually Rei in the show, Rei takes another blow to the integrity of the character.
Rei Q and merchandise... have you ever conceived of a time where Rei is less featured than the other characters? That's how bad Rei Q is - always in stock, always ignored.
You're working with the assumption that they want to make Rei look good or even be good. They aren't - if they were, Rei Q would not exist.
