Of course Brazilians are a fashion - I wouldn't have given it a go if it hadn't been part of fashion / popular culture, because it wouldn't have been on my radar, and there wouldn't have been anywhere to get it done
I suspect it was a combo of magazines, Sex and the City and conversations with friends that prompted me to first try a full Brazilian (instead of just a regular high bikini line), when I was at the salon for my leg and bikini wax. I wasn't dating so it wasn't influenced by wanting to please blokes with an expectation from porn. And DH certainly didn't express a preference for it (actually quite the reverse)
I just wanted to see what all the fuss was about.
Then I discovered how much I liked the result, and how good it felt! DH was a bit forlorn when I first had it done, as he thought it was womanly before. But he recognised it was my body and wasn't for him to ask me to do or not do anything with my body on his account! He got used to the look soon enough - I asked him if he thought it looked pre pubescent, he said that he was a bit startled at first, because he was used to it au naturel before: but that my body and genitals were very obviously that of a grown woman with or without hair, so there was never a question of feeling uncomfortable about resembling a pre pubescent child.
I kept going to get waxed because I really really like the feel of it. No one sees my bits apart from DH and medical professionals - but I'm the one who lives with them and wears knickers every day, and like the feeling better without hair underneath. So yes of course it was influenced by fashion the first time, but I kept going for me (and was enabled to do so because the fashion for waxing meant there were loads of salons that offered it)
Happily, years of waxing meant it stopped growing back so now there's little to no maintenance required to stay smooth!