I don't regard people who follow a trend as being 'weak'. It's about what is perceived as socially acceptable. As humans, we are social animals and on the whole like to conform. There are many very subtle forces all around us which push our behaviour in certain directions. Whether that's following a trend for skinny jeans and not bootlegs or whatever.
It's not that long ago that armpit hair, on display in summer clothes, on women, was okay-ish and acceptable for a good number of women. (I'm talking maybe 60-80 years ago. ) In some parts of Europe it's still 'ok'. Nowadays if a sleb sports armpit hair, it's all over the front of the Daily Fail.
And pubes have gone (literally) the same way. In the past no one would know what women did because the only way you'd see would be in an art gallery or a lads' mag. Or in the shower, with other women.
Now there is porn , easily available on the web and a phone, and for effect, the stars shave it off. Young boys of 12+ who are watching porn think that shaven pubes are the norm. This in turn creates pressure on young girls to conform.
The pressure now, imo, is to shave because this is what young men /boys see as the default setting.
When I've told my DH that, according to MN, some men shave he was astounded. He's never seen a shaved man (in the gym) and thinks the idea is grotesque. He's early 60s.
So imo it's definitely a young person's thing and by young I mean people 40 and under. Yes of course there will be posters here in their 50s and 60s who say they shave but they are IME a minority and bucked the trend of their peers.