Yeah, sorry but I call BS on this too. First, credit where it's due: it is true that straight hair tends
to be softer because sebum is more evenly distributed down each hair shaft (whereas curly hair is bent, and at times, grows out rather than down, so that these natural oils can't take advantage of gravity quite as much). BUT ...
"Soft" is not exclusive to straight hair AT ALL lol. Some of the most crisp, moisture-starved hair I've ever touched is straight. I'd say whether or not the hair is porose has a lot more to do with how soft or rough it is to the touch. And of course, the products/chemicals you use, and how you care for it. Throw those last two factors in and you have a whole lot of straighties with hair that's just not soft.
And preference for "frizz free" hair is clearly indoctrinated thinking. I mean, there is nothing inherently bad or wrong about frizz, and since frizz is indigenous to all sorts of hair (after taking away all the lotions and potions), it's clear that frizz is a natural condition of hair, depending on context. So I doubt anyone's distain for frizz is "natural".
One way we know this anti-curl BS is nothing but a historical trend in the US is by looking at US and European history (in which you'd think straight hair would have been most desired). In past centuries, curls, waves and curly wigs were all the rage. Men thought they were sexy too and I bet plenty of those men played w/those curls and waves. As recently as the 1980s in the US, you were considered sexiest with big, curly hair, and YES, Nicole Kidman did
wear her hair curly back then, with pride. Women couldn't step away from the perm solution. Men played in women's hair, joyously. (Who could resist all those great curls?)
But I'm glad you found out what you like, for yourself
Edited to correct a typo