"I just really like them" probably is the only real reason, unfortunately. People like guns. They think they're cool. They see them on TV. They know they're powerful. Guns make them feel powerful. It's the same type of coolness some people feel riding Harley motorcycles. Or the same type of coolness people used to feel about smoking cigarettes back in the day.
It's all about how they make people feel. Do they make them feel safer? Not me. Living in a house with guns makes me feel less safe. For some people though, maybe it makes them feel safe. More than that though, I think they just enjoy it. It's the reason why they practice shooting so often. It's fun for them. They just really like them.