Any number of comedians would say a hack is something entirely different. Some believe it comes down to being unoriginal - something that has been done before being done again. I've seen a thousand Barack Obama impressions. Out of that thousand maybe 2 were good. I've seen a thousand Arnold Schwarzenegger impressions. Same thing. But if that's "hack" then wouldn't that make abortion, race, and drug jokes hack too?
Johnny Carson was making pot jokes to the point where NBC execs told him to lay off or it might bring trouble. So is it any "edgier" now that marijuana is mainstream or would that indeed make jokes about smoking weed hack? Maybe the mainstream itself is what's hack. Jokes of celebrities, current events, politics or saying the word "hashtag" in a bit are THE mainstream now but if what's new is hack and what's old and worn is hack then...what are we left with?