I agree that people are resorting to vulgarity and use of expletives to create comedy these days. I think it is easier to create a comic situation by doing so. But to say that the audience is supporting vulgarity just because we enjoy a skit or a scene which has a mix of vulgarity or use of expletives in it would be stretching things too far; an action movie raking money at the box office does not make us responsible for or mean that we are supporting violence in movies or in general and so on and so forth. We laugh and enjoy a comedy mainly due to the situation that is enacted and, if I am not wrong, give little (?) attention to the expletives used. We see so many shows and scenes in movies where people are ridiculed for their shortcomings or disabilities and do enjoy them unless they cross the limits. So, as far as creativity is concerned, we really can't draw a line and mark out things this way or the other but those who are scripting or enacting must ensure that they are not creating a mockery of a situation and are forcing people to enjoy. Only clean comedy would get entrenched in our mind and we would want to enjoy it again and again; all others will fade away in due course!
'Not to know is bad; not to wish to know is worse'- African Proverb