From experience, my response to this is, por que no los dos?

I am 100% certain that conservative men being less likely to seek help is _part_ of the reason why various data shows them as having fewer mental health issues than their liberal counterparts. But I doubt that's the whole picture, and it's also by far the least interesting part of the picture - the cause and effect there is pretty simple and clear.

As another commenter in this thread observes, there's "too much psychology talk in every day life, everyone is traumatised and has unresolved issues etc". I think that's part of it as well, and it's not difficult to believe that this is something that impacts "liberal and left leaning men" more than conservatives, due to sheer exposure if nothing else. I think you do a disservice to the discussion if you dismiss this outright.