I suppose organising these sorts of listings just aren't worth the effort considering the amount of people who would actually go to these venues.
I think that when most people want a night out, they'll go and see a movie, or go to the pub - I don't think enough people would make the effort to go to these clubs for the comedy, and they'd be even less likely to turn on their computers to look up a gig guide for comedy event. - It seems a lot easier going down to the club instead.
