More likely, the clientele would reasonably conclude that they must be in danger from a fire in the restaurant. After all, why else would you be carrying a fire extinguisher?
Now replace the fire extinguisher with the gun.
Bob's your uncle, thanks for playin'.
You really aren't as smart as you think. Restaurants are required by law to have fire extinguishers, so that safety issue really isn't. Bob's YOUR uncle, thanks for playing.
We have the right to carry our weapons. We have the right to defend ourselves. chipotle has the right to set themselves up for robbery and worse, and we have the right not to go there.
We still live in a free nation. Get over it.