Do you never think of how others may be effected by what you say, is it not something you consider before speaking?
I think the vast majority of people do think, but you cannot rule out someone taking offence at any remark.
I like toilet humour, due to having read every edition of Viz for the last 25 years, others find it tasteless, lacking decency and offensive.
We do try to accommodate people by having an 'ignore' button on NSC, but it can't work 100% of the time as you don't know who will be offended by what, and also sometimes people want to be offended, if not, the Daily Express and Mail would not exist (and whether you like it or not, the Mail has decent circulation).