I wouldn't defend the Cleveland show. That show is a crime against nature.
The problem is not the lack of jokes in the Simpsons, it's that they tend to be horribly behind the times, unfunny with a punch line that has been done to death in previous episodes or so utterly tame to be on the same level as Airline food. Seeing Homer get hurt and do stupid stuff was funny, but at this point has lost all meaning. Whenever Lisa is on, she will no doubt be inadvertently be promoting another trend or product that doesn't need promoting whether it be Harry Potter, horse/unicorns/dolls, vegan or some baseless midday talk show material. Bart has been dialed back so much, he is a cardboard cut out of himself. Marge is nothing more than a Janitor to the family and an unthinking moraliser. Maggie is a non-entity.
Most Simpson "Jokes" tend to be something normal, but done really ineffeienctly. Example, First Lady Obama visits Springfield elementary to see Lisa, before the helicopter lands, 3 guys zip lines down and spray paints a landing zone. That is not a joke, it's filler, a non-statement about nothing. The rest of the exchange is some moral bludgeoning with random lines that pass for jokes thrown in to see what sticks. Of course when they try to get back on the helicopter the door is stuck, so the first lady rolls her sleeves exposing her biceps and opens the door where 3 guys couldn't. None of this was funny.
You know what was funny? When Lucy Lawless just ups and flies off after spending the entire episode insisting she wasn't Xena. That joke had a lot of setup time and work put in. there was a very real risk it would get lost to people with poor attention spans. The Simpsons has left behind the long joke years ago degarding down to short skits held together by plot no doubt caused but Homer's stupidity. It's not much different to Family Guy now, but at least Family Guy has the guts to tell offensive jokes or play it's strongest card by not giving a ****.
If the Simpsons was nothing but Itchy and Scratchy cartoons, that would be something to get behind.
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