The main reason to separate the forums into topics would be if you wanted to ignore some of them, or only read a specific topic. For those of us that read all of them, it would be more effort to read them all.

That said, I think "flashlights" and "guns" are two that seem to get a lot of traffic on their own. "Guns" is even off topic for this site, but there still seems to be a lot of talk about them here anyways.