If gun owners become a legally-protected class, then private employers would have to respect that.
I'm not trying to argue that this company's actions were smart or moral; rather, that they were entitled to be stupid based upon property rights and the employment agreement.
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
Now what we need is more people adherring to it instead of ignoring it out right.