I also don't disagree with your point. But I am also intentionally informing them how their actions may be percieved by a bystander, or their own potential resource pool.

While they are pre-judging others for not using gmail because they see that as weird, I am a valuable capable potential producer judging them for their failings of both academic integrity (as in you just shouldn't do that simply because it's not right) AND also seperately for their failing of pure intelligence and their own self interest, because in fact some of the smartest most capable people are the ones willingly and knowingly taking on the burden of not using gmail for either practical or principled reasons, and they are filtering those people out, which I judge to be stupid. Those are probably exactly the most valuable people to their own interests.

While from the other side, I don't necessarily consider it to be stupidly filtering out potential employers, because I am not desperate for any scrap of employment.

I haven't noticed any special problem with my own PM address, but I have never tried to cold call anyone from it. So I would possibly agree that filtering out 90% is too much even if I'm not desperate, but I haven't encountered that problem because I'm not trying to contact a large number of new strangers.