The "poor taste" presumably exhibited by some jokes consists essentially in dealing with a topic that is repulsive to some party or denigrates some person or class. Though it ruins jokes to diagram them, let us point out that a common element of the template for jokes is what might be called "borrowed valor": the joke pivots on an atypical and deflating treatment, suddenly revealed at the end, of a topic that the listener is worried about, perhaps subconsciously worried about. So jokes have to be about subjects an audience cares about, no WORRIES about, more than they admit, subjects like relationships, impotence, race, bosses, public exposure of their whatever, etc.. But that is pretty much going to be the same as the list of subjects on which one man's worries are another woman's repulsions: they are the crowd dividing topics, the little pry bars that can be driven into the body politic and humanity in general.
The joke was in such good taste not a single person laughed.
And, of course, death is the great repulsive worry. So much so that in many cultures and communities rational conversation on the matter is brief when it happens at all. I want to put a sign on the wall above my desk which reads "If my work has fallen short of my usual low standards, please reinsert my feeding tube."