It depends on your preference. For me it's just an obsessive compulsive thing to keep skills I don't use at 15.
Me too! I am glad I was not the only one. I don't like getting my level buffed with books and marginal skills. Too many perks and enemies that scale change the feel of the game to quickly.
Block 15 2hand 15 conjuration 15 pickpocket 15 ect ect.
81 perks and an outlandish character isn't my style.
Edit: I particularly avoid the levelups to scale my enemies in the 5 ranges. 30 35 40 45 50 I find that is where big changes occur. and i REALLY despise the fact that all endgame draugr have the shouts of dragons. Really? seems like being a dragonborn would be nothing back in the day when every tom-dike-and now zombie can shout too.