By abridging my right to carry a firearm for self-defense without providing adequate security against violent attacks, such businesses put me and my family at unnecessary and, in my view, unreasonable risk when patronizing said establishment. This would be akin to a business barring its customers from bringing fire extinguishers onto its premises while at the same time refusing to have a sprinkler system or fire extinguishers of its own.
This argument fails a simple logical (and smell) test. Go. Somewhere. Else.
The businesses don't put you and your family at unnecessary risk, you do so yourself by patronizing them. Go elsewhere. Why would you patronize an establishment with no fire control system that barred you from bringing your own, if fire was your primary concern?
"We reserve the right to refuse service to anyone." And I reserve the right to go somewhere I'm comfortable.