Whether it becomes a preference or not, it is driven by culture, fashion and expectations.
In the 60s and 70s everyone plucked their eyebrows to oblivion. It was only old ladies who had bushy eyebrows. Then in the late 80s and 90s thicker, wilder brows became popular. And all those poor people who had plucked them out of existence had to pencil them in.
Now the natural eyebrows look has fallen out of fashion again. Youngsters are heavily pencilling them in.
'Personal preference' for eyebrow shape would mean the none of these fashions were ever followed.
People are perfectly willing to accept that eyebrow shape is culture driven, but not pubic hair.
But that's only because pubic hair culture/fashion is prevalent in pornography. No-one can see your bush whatever you have you done to it. The only time people see these things is in porn. That's the only way it is apparent.
Pornography used to be full of women with pubic hair - the bushier the better. Then the Brazilian came in, and everyone followed suit. Then full shaven came in and everyone followed suit, then 'a little' came in and everyone followed suit.
I don't mind either way. And in terms of whether it's a man's expectation or a woman's preference, you could say the same about high heels, lipstick and heated rollers.
It's the same for hairy man. Hairy chests used to be a sign of masculinity. Now it's a sign of 'poor grooming'.
Culture drives all of it.