Well, worked with a guy at SRS who didn't like to turn on his meter when he was supposed to be looking for Pu-238...but he was a seasoned tech and you asked about new guys.
I haven't worked in commercial NP, but what I've noticed in the areas I have worked is a weak understanding of the fundamentals. For much of my career, I took for granted the depth of knowledge on fundamentals that the Navy expects, or at least expected in the early 90's. There is a difference between training a future HP and training a simple meter swinger. Having a full and detailed command over how our meters operate is a must, in my opinion, which is why I'm so disappointed when I meet a tech who doesn't take the time to know why certain meters/technologies function and respond the way they do.
Something BetaAnt mentioned was techs not knowing how to interpret their meter. At SRS, we had a tech ready to call in an unposted high rad area all because he misread his own meter. Following behind people and double checking their work gets under a lot of people's skin, but my doing so saved him from looking like a dipshit to the who RP section.
The "do we really need to know all this" mentality is a cancer in the HP tech world. As an instructor, I prefer not to entertain such questions, and afterwards am often inclined to throw more crap against the wall...continuing the beating until morale improves!