Except hunting, all entertainment is for kids.
Seriously, I'd agree that super hero films is a bit for children, but adults can enjoy things that are for kids. There's nothing wrong about that, unless you act in your life like a kid. That's another problem though. In this current generation, we've got many that never grow up.
It's every generation. I have yet to see any older generation that isn't behaving like children. Most people never grow up.
If you demand respect or gratitude for your volunteer work, you're doing volunteering wrong.