I agree it principle to have a home inspection  by a professional but I can't fully agree that an experienced tradesman can't conduct an inspection as the Buyer has a right to choose a home inspector or consultant of their of choosing at their sole cost. They still retain their right to terminate a contract if not satisfied with the results of the inspection.

The home inspection process has become an industry. Too many inspectors with below average skills and too many inspectors "double dipping" the consumer by killing the first home and coming across as the savior only to get hired for the next home inspection. Too many "needs further inspection" comments on the reports and this basically passes the buck to another tradesman to make a recommendation.

I have three outstanding inspectors as refferals and if my clients can't book one of them in the due diligence period then I extend the home inspection period until someone I trust does the inspection.

Just my $0.02 but it's my clients best interest at hand.

I agree that the buyer should have the right to hire whomever he or she wishes. And, of course some tradespeople would be fine, many would not. However, in Washington State, if the tradesman is calling any issues of wood destroying organisms or conducive conditions (even basic things like a leaking gutter or downspout) and he or she is not licensed, then it is an illegal inspection and that party will be fined if the WSDA finds out. So, whether the buyer really has the right to hire a person of his or her choosing, does depend very much on the state laws. 

As you say, some home inspectors are better, and more qualified, than others. Personally, I would never kill a deal to get another job, however there are some houses that have died the first time because they had problems. An inspector, who does a good report, should provide the evidence to support those calls that would kill a deal. If it is not there, then the report would be suspect. The market here is such that an inspector doing that would soon have a reputation. As to "further inspection" some inspectors do refer out for further evaluation almost everything, and that is not right either. There are times an inspector really does need to do so, for example to get a problem furnace fixed, however an inspector should be able to make a decision on a number of other matters. One problem is, many of the insurance companies that insure inspectors demand that, if a problem is found the inspector must call for further evaluation. It is all part of the "covering your back" syndrome that we are facing in the real estate field. But I agree, I have reviewed reports where an inspector called for further evaluation by a plumber, when the inspector had a system figured backwards. There was nothing wrong!

I agree pretty much with Steve.  While an experienced tradesman may be able to find some things that lie within his trade expertise, as a thirty year builder who is now a qualified home inspector, I can unequivocally say that only having experience in the trades does not necessarily prepare one for inspecting.  The way an inspector looks at things is very different than the way a builder does.  Many of the things a properly trained inspector looks for can be very subtle.  A builder looks at things based on getting the job done.  An inspector is connecting sometimes disparate clues to come up with a finding.  Ideally, but not exclusively, the best inspector is one who has extensive building experience, adequate professional training, good powers of observation and an inquiring mind.