I imagine it has to do with the spree shootings at universities and churches.What is the idea behind the promotion of students carrying guns.
If a potential shooter knows that there is a high likelihood of dying very quickly without taking many other people out, they may decide not to do it... just take their lives another way.
If the potential shooter decides to take action against others, there's a very good chance they won't get very far and fewer people will be injured and lives lost.
Please note that in Texas, people with concealed handgun licenses must undergo training and demonstrate competency with a handgun. And just because some people don't understand handgun combat tactics doesn't mean that the rest of us are similarly ignorant of them.
As someone who carries a concealed handgun for certain reasons, I consistently analyze my surroundings and develop a plan of action for various scenarios. In the event of something happening, I can react quickly to address the threat, because much of my thinking has already occurred.
And, FWIW, having a concealed handgun doesn't automatically mean you pull it and fire... It is a last resort option when other options as not as feasible. But the good thing is that it is an option when you cannot defuse a lethal situation by other means, and/or the lives of children or innocents are in immediate peril.
But this is way off topic...