I used to work the graveyard shift at a Subway restaurant. I don't know if I would've thought much of full tac-gear customers, but that's me ...
It's sad, but true - wearing your full gear just does draw way too much attention from the (already edgy and) paranoid middle-class WASPs*, but that just doesn't seem fair either. There could be an entire roving band of D&D cosplayers and people just either giggle or feel disgusted. They certainly wouldn't be beaten up by the cops. Since when did ad-hoc relief from reality become more fashionable and/or sensible?
*White Anglo-Saxon Protestants