[Fairfax]

I agree with you Jack Lewis in your "view from Europe".
I witnessed the same shift in Australia about a generation ago.
The most visible part is how sunbathing and the nudist culture it is closely linked to is now regarded as a "feminine" activity.
Sure it was more popular with women but the pleasures of sunbathing (either small swimsuit or naked) were seen as something men could enjoy too. As a teenager no one thought my interest in briefs and sunbathing strange, it was just a recreational activity that some people of both sexes enjoyed.
Sunbathing in shorts or jammers just isn't the same, you have to at least "feel naked" so modern men simply don't participate anymore.
There was a popular subculture around minimal swimwear and sunbathing that todays young males have never experienced. It wouldn't appeal to every man (same as for women) but some of todays men would embrace it if given the chance.