A lot of people like having Carbuncle around, there's emotionnal attachment involved. Removing it completely would disappoint a lot of people. Like I don't think giving it to scholars is a bad idea (even though they can already glam their fairy into one, that's what I personally do), but removing every aspect of having a pet from summoner would remove a big part of its identity.

I REALLY think the solution is to find a way to make it less pointless, if my initial idea doesn't seem appealing to you maybe suggest other things ? Be creative people, there's more possibilities than "remove this or that" or "go back to old thing I liked".