It is raising an interesting issue. I first heard this song one morning after a night on the town. My busking partner, a Texan called Pete Oswald, finally defeated me in an,"I know a more tasteless song than you," contest with a version of this song. It is the sheer awfulness which makes it funny - if you can find it funny at all. I quite appreciate that there are people who never want to hear this sort of thing.
I was recently involved in a debate elsewhere about the merits (or otherwise) af a song which some posters perceived as racist. I think the intent is important. We can forgive misapprehensions, differences of opinion and different interpretations of songs. It is much harder to forgive deliberate spite and cruelty. Satire is on the very edges of this this debate. It has to take risks to be effective. It is very satisfying to be able to come here and read posts as eloquent and informed as the one Bruce wrote before me here.