Kat12, I'm afraid you buried the lede, so I want to repeat it:
I can protect others from my potential asymptomatic/ pre-symptomatic infection, and I want others to wear a mask to protect me from theirs.
It's really a matter of (1) common courtesy to our fellows and (2) of taking responsibility for the communities of which we are all members. Not doing it tells me everything I need to know about the person who's not doing it.