The slogan products aren't for everyone, but there's definitely a place in our society for provocative humour that pushes the boundaries. Translation: if we think it's funny and it shocks people, then that in itself is a good thing --- no matter who gets hurt.
I've seen lots of T-shirts like that overseas that are a lot more out there. Translation: Because this isn't the worst possible example, it's OK.
You hear the same sort of irrational nonsense used to defend absurdly violent video games and movies, and anything else that degrades human beings for profit.