Denver still resents Melo for how he left. Even if he wore a different #, they would still try to find every reason not to honor him. Jokic turning out to be better just happened to be the perfect excuse.
Remember this disrespect wasnt too long ago
I think the disconnect is that Carmelo, the player, has his own fanbase who want him to keep collecting accolades not realizing fans of the Denver Nuggets team, as well as the ownership, still feel resentment to how he left.
Yeah, plenty of other guys who seemingly did less for other teams had their numbers retired but they were usually fan favorites. Leaving how he did lost him a lot of fans there.