John, I've been reading this site "stalking" for about a year. Your question prompted me to register so that I may put in my two cents worth. My recent experience has been with 5:70, the local inspector has "forced" me to re-read various codes, i.e. NFPA 70, NFPA 72, Life Safety 101, NJ Building Code. I've been involved with fire alarm systems since 1978, got my electrical license 10 years ago, and have been UL certificated for burglar alarm systems since the '80's. It seems to me that most contractors, electrical or low voltage type, do not want to raise any questions with the ahj pertaining to "code". As long as the inspector will accept the job, then that's all that they believe they owe to the job. Rather than read the code, and I have to say it is not easy to read and "interpret", they just ask the ahj what he wants, what it takes to get him to approve the job, and that's good enough. If any of this is making sense, let me know and I can continue with my experience pertaining to 5:70, the fire code in NJ.
