I don't think the main problem is the number of mods (assuming mods aren't just being lazy :p). I believe the main problem is what to teach. Sure, there are weapons, armor, fighting, crafting, survival, etc. classes, but eventually ideas will just repeat and things will get dull. Heck, we still don't know much about the world to begin with. There is also the fact that there is no real incentive to go to class. Even if there was fighting during every class, it would eventually get dull as I said before. Of course, the same students would not likely sign up for the same class again, but eventually it will run dry unless the professors is creative enough to keep it going. There is not really anything to be gained or lost by going to, or not going to, lessons (outside of RP points).
For there to be lessons, I believe that there would have to be some sort of reward to go along with it (or consequence if someone doesn't attend). With some sort of stat system, it could be possible to hand out a point or two of a stat per lesson depending on the class. Forcing people to participate is bad obviously, but as long as it's not the same old stuff every class then it should be fine.
If, however, the mods are just being lazy, then I support the addition of anyone who is actually interested in becoming a professor.