First of all I agree that it would be beneficial to make a separate forum for other events etc., and here's why:

The "Wedding / Event Videography Techniques" forum is predominantly made up of wedding related posts as other people have mentioned. I think it might be intimidating to some people who'd like to post about a dance recital video but don't want to get lost among all the other wedding posts.

Vito makes a valid point, more forums to look through is more time wasted, although it makes the information you're looking for a lot easier to find. Some people do events but not weddings, some people do only weddings, and some do both. 2 out of 3 or these case would be more interested in 1 of the forums and wouldn't have to waste time on the other forum, they can just look in one forum and not have to sort through wedding and non-wedding related posts.

I think a separate forum would encourage people who aren't active in the Wedding / Events forum to make more posts about other sorts of events. I personally don't frequent the current Wedding / Events forum but would have a lot more interest in a Live Events, Music Videos & Sports Videography forum.

This is just my opinion. There's a fine line between being a hinder and a benefit... But I guess that's Chris' decision to make.