One of the many great things about The Simpsons was its use of pretty much every form of comedy known to man.  Want intelligent and thoughtful political satire?  Check.  How about some really nasty sexual humor that slipped past the censors?  Oh yeah.  Completely insane (and often monstrous) ideas that nevertheless connect with you the ordinary person?  Indeed.  How about some gross out humor?  How about “yes”. 

The Simpsons was able to elevate to hitherto unknown levels ideas and images that in lesser hands would merely disgust.  There’s explicitly drawn nastiness like the filth encrusted hot dog Apu sells to Homer (“Homer and Apu”) and the twelve foot hoagie that redefined rancid and nauseating (“Selma’s Choice”).  But foul things can also be implied, like Krusty with the “urine” monkey (“I Love Lisa”) and Bart, to the shrieking horror of his classmates, reversing the video of the kittens being born (“Lisa’s Substitute”).  Stuff like this was going all the way back in Season 1, where Wendell vomits on the bus (“Homer’s Odyssey”) and Homer eats a mouthful of bees (“The Call of the Simpsons”).

Some of the above examples are in direct service to the story, others are just there because they’re funny.  But all of them are quick and nothing is drawn out longer than it needs to be.  Another spectacular instance of this can be seen below in images from Season 2’s “Old Money”:

That is shudder worthy disgusting.  The whole reason pills come in those dissolvable capsules is because the stuff inside them in blatantly unpalatable.  (Of course, this particular scene isn’t only gross out humor, it also makes fun of old people for being rampantly pathetic.)  Anyone who’s ever swallowed a pill can relate to how nasty the contents can be and how damned hard it’d be to maintain a straight face while tasting that, much less trying to be flirty.  That is an excellent gross out gag. 

Compare that to two of the most notorious examples of failed gross out humor in Season 12.  On the left we have Homer’s surgically repaired knee from “Children of a Lesser Clod”, on the right is one of the hobo sponge baths from “Simpsons Tall Tales”:

These are examples of gross things that don’t have much humor in them other than just being gross.  In and of itself that wouldn’t be too terrible, but each one drags on to kill screen time like you wouldn’t believe.  The hobo bath isn’t only long, it also occurs twice.  Homer’s knee is first gawked at by Milhouse and Ralph and then scabs over Ralph’s hand for no real reason.  In each case there isn’t anything else going on.  There’s no subtext or insight, both are just random and have nothing to do with anything.  And, most damningly, they take a long time despite the fact that there’s no joke to either one. 

Like physical violence, gross out humor is a comedy form the show once handled with scalpel precision and now uses as a cudgel.  Sadly, and like physical violence, the decreasing precision has also been accompanied by an increase in usage.