It is to be expected. If you allow guns somewhere, where they were prohibited before, there will be a push back. It is not unreasonable turn of events, whatsoever. It should have been expected.
In addition, whenever you will find academia, you will mostly find that it is against any forms of harm (unless they are paid to research by DOD, to develop some new kind of weapon).
I'd like to also add, most professors who have tenure, they are given a huge leeway to do what they want, how they want, and how often they want in relationship of their own classes. Therefore, it would seem to such professors that inability to dictate their own policy in their own classes as tyrannic.
Add all these together and you will have very unhappy professors. Again, it was apparent to happen, no surprise here. They are testing waters to see what is a new limit to their reach.