Whats the problem with Speedo and Americans? ;)?
I’m an American heterosexual male and I wear speedos/briefs because I find them comfortable and practicle. I find your observations to be quite true. I think the reason Americans tend to be shy about guys wearing briefs is because of the feminization that has occured since the 60’s regarding men. Wearing a speedo makes it quite obvious that we are men and our maleness bulges. Since the 60’s the role of a male in America has shifted and we are no longer supposed to be the strong, courageous one. Now we are supposed to be softer like women and women don’t have a bulge there.