I’m not a “pro-gun” person (although I’m not opposed to them if reasonably controlled). But I think that the way that argument goes is that it is easy to get on the “list”, even for very specific issues unrelated to being a threat. And once on the list, it can be hard to get off. Same argument for allowing people on the no-fly list to get guns. Not saying I agree with the argument, just sharing what I’ve heard.
I have difficulty seeing someone mentally ill enough that they can’t handle their own fiances, yet not so mentally illegal that can’t handle a gun.