Speaking from the home inspection community I could shed a little light on the HI side. It is in our inspection standards to do a visual inspection. There is no way we can attempt to be experts in all of the fields we inspect. Then again, if a homeowner wants to do it right they could hire 10 inspectors from all of the different construction trades and spend a fortune in inspections. There are some inspectors that feel like they have never had a job with any authority and now that they are home inspectors they let this job go to their head. I feel like I do have a fairly high level of competence as an inspector. But imagine trying to keep up with, not only electric code, but plumbing code, codes local municipalities adopt, etc. It would totally be overwhelming. The inspector that respects that expertise of the individual trades is the guy you want to hire. Unfortunately the players in a real estate transaction can negotiate or do anything with the information the HI provides. Some completely ignore it, others make a mountain out of it. For every idiot HI you run into you can find a humble inspector that's probably more knowledgeable that the idiot because he's more open minded.