Overreaction? It was a business decision, pure and simple, and it is not for us to judge, one way or the other.
I will respectfully disagree with this. It is most certainly up to us to judge and hold accountable any business that has in place a policy that we disagree with. I voice my displeasure by sending very polite messages and by refusing to spend my money in such establishments. While they certainly have every legal right to post sign banning firearms in MOST states we need to make sure they know there is a percentage, however small, of people that are taking their money elsewhere.
Will it do any good? Nobody can answer that question. It has worked in the past and it will work again.
PS If I owned a business and two guys walked in like this then I would demand that they leave immediately. Not because they had a gun but I don't want or need idiots in my place of business. I sometimes OC and have never had a business owner ask me to leave.