I agree that on the scale of sexist behaviour what happened here is mild. I also agree that it's unlikely Tim meant to offend.
But if a choice of words does cause offence (or causes a reader to never come back) isn't it a good idea to adjust them? I called attention to it to encourage Tim and Reg readers to think about the effects of what they say.
If I pointedly ignore you when it would be polite to acknowledge you, is that OK because I "clearly never meant to offend"?
If I call attention to habits and ways of thinking that are mildly sexist, I hope that would encourage people to think about what they do and say, and with a little awareness there might be fewer "real cases". I don't see how calling attention "undermines" real cases, unless you have an injustice awareness limit, so after you've had your fill of minor cases you will tolerate major ones.
I suspect I'm not the only one to think that Tim's words were already a sexist issue and I didn't make it into one. Indeed, one other reader has taken the time to say they agree with me. If your interpretation is different to mine, it might still be useful to know not everyone thinks that way.