Characters with 16 or 23 INT face a dilemma where they have to choose whether to spend 2 vs. 3 or 1 vs. 2 practices. Daevryn and Linolaques have suggested that it's almost always preferable to spend the lower number and just accept the additional delay on perfecting the skill.

So take away the dilemma. It's the same argument for why drow thieves and assassins should get sneak at 100%: so they don't waste practices on it by mistake or out of ignorance.