If businesses don't want customers who carry, there's always another store or restaurant down the block that does. Maybe 5 - 10 percent of businesses around liberal Phoenix have signs.
As far as jewelry stores are concerned, that's where I think I've seen the most people carrying openly - behind the counter.
I still think the most important aspect of open carry is that it prevents people from being harassed or even arrested from not successfully carrying concealed. I've heard horror stories from other states about people actually being arrested because someone saw their weapon. It gets warm here. T-shirts "print" quite easily. Even if someone isn't carrying openly, it's not uncommon to see the butt of their weapon showing through their clothing.
“...there’s always another store or restaurant down the block that does.”
Always? You seem sure that the whole world resembles your neighborhood or places you know about.