I can't speak for the reaction of "Match Game" contestants, especially when the audience would boo an answer that wasn't raunchy enough, nor can I speak for "Feud" contestants on the receiving end of Dawson's putdowns (and I want to add that the thing I posted about Dawson's response to a couple of advertisers' protests about a tasteless remark he made about Henry Kissinger in which I said, roughly, "guess you can do that when you're the number-one daytime show," was intended as sarcasm directed at Dawson). What ticked Dawson off would be a question like this: Name a country in Europe; top six answers on the board. The family gets England, France, Spain, Germany, Italy, then blanks on the sixth one. Somebody says "Denmark." Dawson knows that's a country in Europe, and while it's a little out of left field, it's still a valid answer that, in my example, just didn't make the survey. But if the same person says "Japan," Dawson might suggest the hapless player go back to school and relearn geography. That might have seemed fresh at first (an emcee who lets a contestant know when a wrong answer is twenty miles off the track) but I think it got to be a turn-off after a time.
As for Groucho's contestants, they were always told beforehand not to get mad if he said anything; it was all in fun. The people no doubt knew Groucho's character from the movies and those who didn't receive a mild putdown were usually disappointed. But even Groucho once said he had to draw the line. George Fenneman and, before him, Margaret Dumont, were pros and almost like family to Groucho. But, Groucho once said, he had to watch what he said when the contestant was not in show business; there was always the chance they'd take it the wrong way. Marion Pollock, who wrote the questions and stayed with the contestants to keep them relaxed before facing Groucho, once said that most would come offstage saying, "It wasn't so bad."
Another host who didn't mind injecting a little sarcasm was Bob Eubanks. He once said he wished a husband on "The Newlywed Game" would take a swing at him, then leave and not come back. Eubanks thought it would be funny to see four wives and three husbands onstage.