The article ("Don't Do It! A sour-faced guide to conventions.") is a satirical glossary for sci-fi convention-goers and seems to imply that No Shame Theatre was attended frequently enough by sci-fi fans at conventions that they needed to be warned about it.
No Shame Theatre
A bunch of wannabe actors/comedians putting on a hastily rehearsed and hopelessly underwritten collection of sketches for your amusement. You won’t be. Suggest they go and shove a “Klingon Surprise” (“out of this world jacket potato with a galactic choice of fillings”) where the sun don’t shine.