Yes, there is a lot of media-driven BS regarding mass shooters, which actually aren't responsible for thousands of gun deaths every year. Most people in mental health circles are focusing on all of them, with the understanding the mass-shooters are the minority of the issue.
The psychologist who is promoting 7 sexes is a nice strawman, but doesn't address these gun issues in any way. There is definitely evidence that sex/gender isn't binary (in many species), but I'd like to see your evidence that psychologists aren't the folks who should be providing insight into these mental issues, and providing the best evidence-based practices to deal with them.
Also, the smallest category of deaths (from mass shooters) are the ones your talking about in gun-free zones. Most of the thousands of gun deaths every year are *not* in gun-free zones. This is the paradox that must be dealt with in regard to those that want more gun control.
Anecdotes are fun to talk about, but they certainly don't describe how most of the system works. And you will be arguing against people who believe the exact opposite, with a powerful statistic on their side...thousands of gun deaths ever year *not* in gun-free zones. How should we handle this dilemma?
The sex/gender issue is interesting and important but will get us way off track in a hurry. Perhaps I shouldn't have raised it at all but it is a sore point for those of us with a traditional point of view who are having an alien and (to us) morally wrong outlook forced upon us.
Can psychologists reduce the number of gun-related deaths? Some undoubtedly but how many? And how much freedom should we give up to in an effort to save more? Abdicating more and more authority to psychologists is a mistake IMO.
With all due respect to your profession, it poses a danger to our civil liberties. There is a thin line between it being a benign and caring profession and one which becomes a tool for statists. Are your professional societies pro 2A, neutral or anti 2A? Perhaps the answer is not clear cut but I do believe that many psychological "truths" are shaped by politics and economics rather than being a matter of verifiable scientific study.
We must not abdicate too much power to psychologists and psychiatrists who even with the best of intentions are not able to predict human behavior. The danger is one we are already seeing with the VA and our veterans - preemptive gun confiscation. This evil needs to be reversed in a hurry else it take root and spread.
"How should we handle this dilemma (of thousands of gun deaths)?"
Your question reveals the stress and pressure of your work. Thank you for what you do to try to help people in extreme circumstances. I do not know if we are facing an epidemic of murder and suicides in historic terms (my hunch is that we are not) but I am certain it seems that way from the perspective of mental health professionals. Instead of expecting you to do more, the answer is to restore the network of love and caring found in intact, healthy families and communities. You can't do that. It is the individual responsibility of each of us.