The era of Marvel Studios struggling with their villains is mostly over after a run of successes from Helmut Zemo in Civil War onwards (with a few lesser ones thrown in there, inevitably), but there will always be some fans who refuse to let the earlier issues lie.
It doesn't help when the film-makers themselves start bad-mouthing their villains, either, as Peyton Reed seems to have done with the first Ant-Man's villain Yellowjacket. He says he wasn't a fan and that motivated him to go a different way with the sequel - which is said to not have a conventional villain.
Though his version of the movie was distinctly different to the original vision, Reed inherited the villain from Edgar Wright before he left the project and he doesn't sound entirely enthusiastic to have been "lumbered" with him, as he told io9:
“The villain in that movie felt like a bit of a vestige from the era in which that project was started, [which was] around the time of Iron Man one, where you have an antagonist who has a similar power set [as the hero]. I was hell-bent on doing something different in [Ant-Man and the Wasp].”
The truth is that Yellowjacket wasn't a BAD villain per se, he just wasn't a particularly memorable one. He had the same personal interest markers that the other more successful villains have had, rather than just a cartoonish desire to take over the world, but he wasn't really developed enough for anyone to care.
Let's hope Reed used the lessons learned to inform his approach to Ant-Man And The Wasp WHICH WE STILL DON'T GET TO SEE UNTIL AUGUST BECAUSE OF THE BLOODY WORLD CUP. Not ever letting that go, to be honest.