Masks a trail head parking aren't ridiculous but getting close. While you get ready to go....OK possible. Coming back while cooling down and possible breathing hard...yeah, that's would be an unrealistic expectation. I'm not (and I don't expect anyone else to) stop 1/4 mile from the lot, fish out a mask from my pack and try to hyperventilate through that sucker for the last bit.
At a certain point it has to boil down to this.
- Don't go to places like this if you are uncomfortable with it
- Feel free to leave if you don't feel comfortable with the scene
- If you do go, and stay, keep your respectful distance from people for their sake and yours. Take another short loop even if you need to wait out a few parking lot folks.