My problem with Whataburger is not that they decided to restrict OC, or even that they are doing so by talking to customers instead of posting signs. My problem is how they went about it.
If you remember, Whataburger publicly announced that they would not allow OC right after the law passed, which was around 6 months before it would even take effect. A rational approach would have been to allow the law to take effect, see if there were any issues, then make a decision. The only reason to make a knee jerk decision and then publicly announce it 6 months ahead of time was to send a message.
I'm not sure if this was simply driven by a childish reaction to a decision that they didn't support 100%, if they were pandering to the anti-gun crowd, or if there really is an anti-freedom sentiment among the leadership of that company. But whatever the reason, it was a slap in the face to those who believe that the purpose of government is to secure the rights and freedoms that we are born with.