I think Reno is saying a guy who sleeps through a CEU course doesn't suddenly aquire ethics and being good at standardized tests does not guarantee skill in a largely mechanical trade.
I get a chance to watch these guys working around the neighborhood and the worst crook I have seen was licensed. A complaint to the DPBR still didn't make him do a decent or code conforming job. The trunk slammer my neighbor hired to fix the EC's work did a lot better job ... for a tenth the money.
