The thing that annoys me about the "fun" description is when it's used to invalidate any actual criticism someone might have.
"I like the humor in parts, but I think they told TOO MANY jokes which kind of undercut the story."
"Well sorry, it couldn't be dour like Batman vs. Superman or some kind of serious Oscar movie, guess you hate fun."
As if there isn't a middle ground that plenty of MCU movies have hit.
"The third act was way too messy."
"Well, it's a superhero movie, what do you expect, they're all like that. Ugh, I bet you went in wanting to hate this, sorry, some of us actually like having fun."
^ Sadly, those aren't hyperbole.