For example, the next guy who walks into his place with a sidearm on his hip is going to be less welcome than you were.
Face it, you screwed up, and hopefully learned a lesson from it that you can pass on to others, including many in this forum.
I once went to an all-night diner in Fort Worth, Texas called The Pink Pony with my wife and one of her friends, and all I can say is I'm glad you weren't there, because everyone in the place was drunk and rowdy, including the three of us. The management didn't mind, as a matter of fact they expected it. It was 1:00 AM on Sunday morning...
What about all of the lunch counters in the south that refused to serve blacks in the 60's? They were forced to integrate at gunpoint. Any establishment open to the public must accept any law-abiding customer. I was a law-abiding customer.
The "No shirt, no shoes, no service" might well be as illegal as "No blacks."