It depends on the character and class for me.
Fighters and Rangers I tend to give short and sensible haircuts, or at least tied back. Wizards and Clerics I'll go with either elegant and elaborate or long and mystical. Rogues and Warlocks get whatever I apply to their concept, from elaborate con artist to scruffy urchin and mad zealot.
Yes, i agree. I definitely see some classes, like wizards having more .. eccentric hairstyles. Having 3 options "long, short, none" was an exaggeration. I just don't care for all the kids and their over the top haircuts. Kinda ruins the immersion. My point of reference for a fantasy setting would be something like the lord of the rings trilogy.
(I just realized this has nothing to do with the suggestion)