I think it's fine to debate the reasonableness of a position. I don't think it's meaningful to debate whether someone else is wrong because of how offended you are.

I think one can use one's sense of offendedness to measure how diplomatic someone else is... but that's not especially useful outside of social niceness.

"I think you're being offensive" is not the same as "I think you're being unreasonable" which is not the same as "I think you're being oppressive".