I don't get it either.
Then again, I don't get Everybody Loves Raymond or King of Queens.
Well, I do. In the former, our protagonist goes out of his way to avoid his awful mother and in the latter we're supposed to marvel at just how that fat, lazy, philistine managed to get such a hot wife.
However, those are literally the only jokes. Utter one trick ponies and yet those series have gone on for years.
Even at the more intelligent end of the spectrum, I do not understand the acclaim that was heaped upon Arrested Development and 30 Rock.
I enjoy Seinfeld, Frasier, Curb Your Enthusiam etc, but some aspects of American comedy continue to confound me.
I have no doubt that Americans would say the same about My Family or Two Pints of Lager and I'd have to agree with them.