This is a very odd disclaimer. It seems like a reasonable warning at first glance, and it's probably meant in good faith, but if you break it down into it's meaning and intent I don't think it's so innocuous. In fact, I think this is one of the most awfully passive-aggressive statements commonly repeated among people of otherwise sound judgement.
Who self-identifies as easily offended? Nobody.
What you are asking really isn't that people do not read, because there is no set of people that identifies with the warning. You're not even asking for forgiveness for whatever distasteful communication is to follow. You are in reality warning your reader, viewer, or listener that if they have a problem with whatever offensive material follows then it is because of a flaw in their own character. They were easily offended.
The fact of the matter is that you are being offensive. Wilfully offensive. Your disclaimer is in essence a threat.