It sounds to me like people get hurt by microagressions because they have been taught that microagressions exist in the first place. That is once you have been convinced that microaggressions are a problem you will find them everywhere, since they are primarily a matter of interpretation. The entire concept then creates a negative environment where everyone feels they need to walk on eggshells all the time. This is more unhealthy to society and groups, than the microaggressions. It creates distrust, where assuming the best fosters trust. I see the entire concept of "microaggressions" as a downward spiral.