I think there’s a fear factor. What I don’t know....sort of like the raccoon covering his eyes and thinking you can’t see him.
Let’s face it. Going to the doctor, at best, can only result in a neutral result: you’re not dying....yet.
Irrational? Absolutely. But related to some “macho” ideal? Hardly.
I don't think it is due to fear -- high status macho types would be the least fearful class of people (other than madmen, who probably also don't visit docs, unless dragged there by cops of family).
As someone fitting the profile to a tee (a CTO and chief scientist in a computer company, with a strong inborn 'macho' attitude, which greatly annoys my wife even though she admits she picked me out for it, go figure), I also didn't visit docs for couple decades, since graduate school (except for visiting my parents, both medical doctors, but only as parents; I do visit dentists every 5-7 years, but only with specific tooth to fix), I can introspect it in myselfs as a strong aversion to letting someone take control of you. I also don't fear of death and can tolerate pain well (e.g. I don't take novocain for any dental work, or any pain meds for anything in daily life). I just put up with pretty much whatever ails me, fix as much as I can figure out how and then let it heal over. When my time comes, I will just go.