When it comes down to it, the people who are doing the hearing determine what is acceptible and what isn't. You can cry "but there's nothing wrong with what I said/sang." Fine, if there isn't anyone besides you involved in the communication process. (Are you singing in the shower? If not, you're going to hear about it.)

It may be self-censorship, but it's more like putting a filter between your brain and mouth. Listeners need a filter between their ears and brain. It helps if both sides can try to understand the other.

At one extreme, you wouldn't tell jokes about someone dying to a person who has just lost a loved one. It would be worse than insensitive, it would be cruel, because you'd probably know before you decided to tell the joke that it would hurt the person hearing it. I can believe there are people so dense that they don't even think about it. ("Who cares what he thinks, I think it's a hoot.")

At the other extreme, there are people who seem to get a thrill out of being offended, and look for opportunities. I've met a few. One was offended that "black" was used to describe bad things. (As in "My, you're in a black mood today.") He just didn't believe that the term "black" could be used without implying race. Of course, he also told me that the Smurfs were Satanists.

There are messages/songs/jokes that can hurt people, and it's common human decency to avoid that. You'll have absolutely no success telling people they don't have a right to feel hurt, and people will strongly resent it. There are messages/songs/jokes that offend people sensibilities, and while it's a good idea to try to forsee that, it may just be that the offended party's sensibilities are simply set to level 10 on the old "offence detector." In any case, it's not only the speaker's responsibility to try to be understandable (avoid misinterpretations), it's the hearer's responsibility to try to understand. Unfortunately, both sides often seem to think all of the responsiblity is on the other side.