This is largely true, but there remains the issue that there are some people who, for whatever reason, almost seem to go out of their way to assume bad intent and interpret what was said or written in the worst possible way.
There is probably some sad history behind many of those individuals, but reasonable people can disagree about how to deal with the situation.
The current fashion implies that as soon as one such person enters the community, everybody has to start metaphorically walking on tip toes.
Maybe a better outcome overall would be for the person to get therapy.
Everybody has a line somewhere for what they consider "too easily offended". This is true even for the staunchest defenders of the current fashion, because even they understand implicitly that offense can be faked.
So yeah, you need good defaults, but that's really a discussion about where exactly that line should be drawn. I doubt either extreme is the right answer.