South Park is a better show than you give it credit. They frequently explore serious issues in earnest and I have often felt the gravity of the message outweighs the humor in its presentation.
Regardless about how you feel about Uber or its competitors, I do not believe they actually endorse rape or are capable of hatching a plot to plan a real life rape to occur as a publicity stunt. This is what was described in this thread. And I found it disgusting, even if it were satire.
But I guess some folks on HN don't really take this kind of thing seriously.