I know Psychic Fangs can be bred to Carvanha and Lillipup, but I'm sure there's a lot of other things with sharp teeth that would probably love that move.
As far as things in Gen 1, don't forget that there was no breeding to pass moves around (plus I can't imagine anything from back then other than Cubone or Marowak using Bone Club or Bonemerang, so at the time, that one was justified). They also were working with some serious data limits back in Gen 1 and 2 (it took using a new compression technique to even finish programming Johto, and by chance it allowed them to put Kanto in G/S/C) so they just could not program large movepools at the time (still, I hate that some things that evolve with stones get NOTHING by level after they evolve, they should really fix that).
I guess a lot of it is trial and error by Game Freak, trying to see how things work and go from there (generally this is where the Move Tutors or mid-generation changes in movepools come into play). Still, I bet there are at least a few slow Rocks that wouldn't mind Accelrock to catch stuff off-guard, and definitely Psychic Fangs could use more coverage than it does now.