100% agree that any stigma against being a stay at home dad (viewing the issue from the opposite angle as you ask) is also unhealthy. In my personal journey, at least, I have not encountered men who stigmatize my desire to be a stay at home dad but I have (surprisingly often) encountered women who stigmatize female homemakers (or the concept thereof). I guess it’s only anecdata there, but I don't think I’m wildly off base with my experience.