Comes down to what you're willing to take really. I don't use mesh, never have, and being shot in the face has never really bothered me. I've been smoked with .28's at less than 15ft. without skin breaking and I just keep my mouth closed when in play (force of habit from fighting).
Hell, in all my years doing airsoft I've only used full seals a few times. Just purchased some new ones because more fields are getting really strict with that rule, but since I was 14 I've never caught one to the eye while wearing ballistics, and I seem to get hit in the head very often.
Personally I would rather take those shots than getting hit in the ear lobe from 30-100ft.
My point in all this being: People are sensitive to different things in different areas. As ThunderCactus put it; personal protective equipment is each player's responsibility. If you don't want to bleed from or be picking styrene from your face after a CQB match or even large field milsim, wear mesh or another mask. If you have a tattoo on your forearm you're worried about ruining, wear long sleeves. It's common sense to protect yourself from things you want protection from. Unfortunately in my young age I have realized that common sense just isn't all that common.
However, I digress..
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