Fanjo
Speaking as someone who grew up in the UK and now lives elsewhere, my view is that British people generally are extremely mealy mouthed, without being noticeably less racist, sexist, ageist or any other particluar ist compared to where I live now.
It's not right to go around offending people. But also, it's not right to be unable to laugh at yourself. Everybody should be able to do that, including those who identify with any particular minority, and in my experience, they do so more in other countries.
My view, which I don't expect you to like, is that British society now encourages people to identify with all manner of particular groups who percieve themselves as victims, as there is now such an public emphasis on handing out sympathy to those groups. Doubtlessly you will say this is right, and I agree up to a point. However, when it dominates public discourse so much that real issues such as dealing with the rich-poor divide for example get squashed out, it goes too far. When it gets allied with the massive emphasis on politeness in the UK (not a bad thing in itself) it gets pretty stultifying.
I sometimes find myself shocked at 70s attitudes, but likewise, when I read Internet discussions amongst people from the UK, I find myself shocked at just how quick some people are to take offence, as if it is a virtue to be offended, although I suspect people are a bit more relaxed in RL.