For CND a thorough and gentle prep is taught ... whether you do that wet or dry is up to you as long as 'mission accomplished'!
I use both methods.
A new client I always use Cuticle Away and do a wet prep because they need it and I would have to be too aggressive if I did it dry .... but once a client is a regular I rarely do a wet prep as it simply is not needed. The clients have their nails done every 2-3 weeks and the build up is not difficult to remove dry.
I know what I am doing and so do you but for students, it is such a help to use Cuticle Away because it teaches the student good habits and does the work thoroughly and gently (which is why this method of prep is taught by CND) ... with more experience and having learned to care for the health of the natural nail during prep, then they can learn what you have learned and use a dry prep if they want to and if it is appropriate to do so.