Try looking at it in reverse: the stress you feel about "microaggressions" is similar to what people are complaining about. It's a minor thing, something you can live with individually, except that as a constant daily drumbeat.

Microaggressions do exactly what you say: force people to feel as if they're walking on eggshells. And telling them "Oh, just shake it off" gets exactly the same response as if I told you to just shake off the accusations of microaggressions.

The downward spiral already exists: people do exhibit a range of racist, sexist, etc. behavior on a spectrum every day, from outright asshole behavior to small, incidental assumptions about people that make them feel unwanted and singled out. It afflicts some people more than others. So you can take this as a thought experiment to see why it's a problem for them, and if "just ignore it" doesn't work for you, then maybe we can find a better answer.