Here's a list of 5 reasons why.
1. Your Not Helping.
The #1 misconception is that a shouted out, (usually drunken) verbal abuse/comment is somehow helpful to a comedians act on stage. This is pure bullshit. Heckling is not helpful or sought after. It doesn't make the show better and it's not showing anybody how clever you are. You want to help? keep your comments to yourself, clap your hands and most of all - just laugh dummy.
No. Crowd work is crowd work. Heckling is heckling and never the two shall meet. Here is the difference. Crowd work will always be initiated by the comedian. If comedians want your opinion on a topic THEY will ask you. Sure lots of comics do great crowd work, and yeah sometimes it can be the funniest part of the show. But it's always their job to start and control that - always.
3. It's Funny.
Nope. The heckler is NEVER as funny as they think they are. Never. Again, it's an uninvited interruption, it throws the comic of his/her timing, can break concentration and at worst stops a great show in it's tracks. Sure, sometimes the shutting down of a heckler situation by the comic can be super funny, but that has way more to do with a comedian's skill set then heckler being a jackass. Which leads into reason # 4.
Some comedians are so good at dealing with hecklers that it might seem like it contributes to the show or that the comic enjoyed the interaction. Nope, it just seems that way. Comics are good at dealing with this because they have to be, not because they like it. And it takes years! Years of dealing with dumb assholes yelling out dumb shit. A real comedian wants to perform his/her material and get a point of view out there. The ultimate goal is to connect sincerely with the entire audience not verbally wrestle one idiot into submission.
5. It's disrespectful.
Ultimately heckling is just disrespectful. To the comedian, the crowd and the venue. It's just plan rude. And you will get dealt with one way or the other. Some clubs have a zero tolerance policy. Do really want to get kicked out of a club because you or your fiends couldn't shut up? Also it pisses other people off - pure and simple. I've seen a heckler get a beer dumped on her head by other patrons. Fistfights, security ejections you name it.
Bottom line is that if you don't like a comedians material there is a simple way to show your disapproval... Silence. There's no better way to for a comedian to figure out they are on the wrong tack then zero laughs.
James Allen Kamp
James Allen Kamp