I enjoyed the Snyderverse movies but they weren't really Superman films. It's not supposed to be dark and serious.
I think people that didn't enjoy this film need to try and approach it from a different angle. It's a comic book movie, it's supposed to be campy and goofy. More importantly, it's also a Superman movie, and I think people tend to forget what Superman is supposed to be like because of the Snyderverse and how dark some of the other DC stuff is (like Batman).
A big part of Superman's persona/aura is that he is just...good. He is so purely, childishly good that it flies way past the point of absurdity and even humanity, which is appropriate because he is actually a goddamn alien.
If your kids are enjoying this and you're being a sour puss about it, they're reading a comic book and you're stubbornly trying to watch what you think should be Citizen Kane.