Blind par threes are (mostly) a survival from nineteenth century golf. Colt and his ilk removed the overwhelming majority of them in the first three decades of the twentieth century. And there were a lot -- most pre-1900 links seem to have had one at some point. That surprised me at first, but then I thought about it for a while, and it all became pretty obvious.
Golf in the nineteenth century was overwhelmingly played by men, and men were in those days broadly the same as they are nowadays. It is, when you think about it, entirely unsurprising that, if you're strolling through a patch of sand dunes looking for golf holes, and you have equipment -- hickories and gutties -- that makes getting the ball airborne difficult, someone will look at the tallest dune on the property and say 'I bet I can hit my ball over that and you can't'. And that's why the famous blind par threes came into existence.