Many silent comedies were slapstick comedies, while many sound ones from the 30's and such were screwball. They're not my type of comedy either, but they are still good/great films (depending on which you're watching). In fact, the Marx Bros. are the only ones I really laugh at heavily, but I don't dismiss other ones as bad because of the generation gap. It's their charm that I admire, especially films like The Philadelphia Story.

I've noticed that 90% of the films you've seen from the 50's and before were "good, not great" or something similar.