Never noticed this before, probably because I only use cloth/wool, but I started a new game and because it was really cold I had to make some right away using leather (the only available textile I had) and ... voila ... no option there. I checked all other items that can be tailored and no problem with leather.
No mods, no nothing. Though I am playing in a map with the ancient shrines bug
It's WAD that you can't make tuque's out of leather. Tuque's are knitted as far as (the very little) I know (about tuque's), and you can't knit with leather, hence WAD that you can't make tuque's out of leather. Here are some previous bug threads where this issue was mentioned/reported. You can see that both were closed, and one done so by a dev (which is a good indication that this is WAD and not a bug).
https://ludeon.com/forums/index.php?topic=17056.0
https://ludeon.com/forums/index.php?topic=16777.0
So I'll be closing this one as well now for the same reason "not a bug, WAD". Thank you for reporting it though all the same.