Every time folks see those signs, it reinforces the concept of "We don't want guns here."
Which makes it that much harder to persuade folks on the issues.
It only takes a few seconds to ask a store owner or manager about "Hey, why don't you want my business?"
Now...
What NATIONAL chains are nationally posted? I'm having a hard time thinking of any... I know that some Wal-Marts, Home Depots, etc., have -been- posted, but when someone contacted corporate management, and the corporate folks had their come-to-jesus meetings with the store managers, those signs came down...
Small stores, and even small chains, are scared to death of the megachains, and with good reason. If Joe's hardware posts, remind him that "Hey, Lowes and Home Depot want my business more than you do - it's going to make me feel bad to go to them, but if you insist..."
These owners and managers are not psychic.
You have to talk to them to let them know that you are not happy. Be nice. Be polite. But be firm.
Some of them will give you BS excuses, like their insurance makes them do it. I know shooters who are in the insurance business, and they NEVER heard of that... Most of the folks with the signs up think that they're being safe. Or they think that they are required to put them up for some reason. Remind these folks about Lowes, Home Depot, Wal-Mart, or whatever, again. And ask them again why don't -you- want my business, when the folks in Bentonville welcome me?
When the signs come down, we're winners. You may not win them all, but you'll win some. Feels good.
If you do nothing, and the signs stay up, you lost, because you never even tried. You forfeited what might have been an easy victory.
Are you a winner? Or are you a loser? It's your call.