Don’t fall for feel-good, easy do-nothing solutions like gun control, especially when doing so will be harmful to the vulnerable. Look at the actual causes.
Any reform that doesn't create a Utopia is worthless #18,008,675,309.
I mean, sure, the availability of guns does not alone give mass shooters the desire to kill. Alienation caused by capitalism, a culture that glorifies violence, a desire for retribution against an unjust world, and privilege all do that. I could add more things to your list, but I'm sure you'd find a way to relate them to capitalism. Gun control will not remove anything that gives the desire to kill; it will only take killing more difficult and slow.
But you're basically assuming that treating the symptom is never worthwhile. This ignores the fact that there are people living under toxic gun culture right now. The Communist Revolution, if it ever happens at all, will probably take longer than any of us will live.
Sacrificing people in the now on the altar of your glorious future is a bit fanatical.