Because the Excelsior was demonized so much in Trek III I always hated it. However, how it was treated in VI as Sulu's ship kind of redeemed the class. It still looked wrong as the basis of the Enterprise-B and was clearly evident as a cost-cutting measure rather than making a new model.
I never hated the Excelsior
and remember being happy that Sulu was its captain in Star Trek VI
. It was Styles who bothered me. I hope Starfleet punished his incompetence by taking away the swagger stick that he always carried with him.
Yeah, the Excelsior-class was a cool design and was a worthy successor to the Constitution-class. Any demonizing of the design likely was the result of Styles' boasting of the ship being superior to the Enterprise
and Scotty's somewhat negative view of the Excelsior
and subsequent sabotage of her.
"...if my grandmother had wheels, she'd be a wagon."
"The more they over-think the plumbing, the easier it is to stop up the drain."
--Captain Montgomery Scott
So there's probably some irony that the Excelsior-class ultimately became a mainstay of the fleet for the better part of a century.