Lee, I understand what you're saying, but there are a few variables at work.
There may be a few things going on with a newbie.

How new is new? How long have they been trying to be an adult webmaster?
How educated are they? Some college, high school, self taught (6th grade)?
Perception (How they understand what they're being told to do. Maybe they don't understand exactally, but SAY they do, when they really don't)
Is there a language barrier?
Are they full time, part time or mini time webmasters?
How much time do they invest? And, how much money?
Age may be a factor too (maybe they're not "ready" to listen and learn)
Who else is advising them, that may have a differant opinion then yours?
Are they naturaly lazy, or do they like to work 24/7 like some of us fools...
The list goes on....

Yes, it's hard when you tell someone soomething and they don't listen. Or, you think they're not listening.
I get that even at home when trying to teach one of my partners something. From webmastering, design, to buliding, carpentry to plumbing...

Everyone takes what I say differantly