Home Inspection General

As he pulled up to our house I noticed that his truck said he was a plumber. So I wondered why he was hired to do a home inspection.
His first comment was that He said he would not be going up on the roof because it was too steep. The home inspection he wrote was 76 pages long. Most of it was disclaimors saying his company was not responsible for the findings of the inspection. That was smart of him because about 50% of his statements were innacurate.
 A few examples:
He said there were no Carbon Monoxide detectors in the house - We have 3.
He claimed that our gas feed pipes into the furnace, dryer and water heater were rigid. - They are flexible.
He did say that our gas oven works fine - It is electric.
In several places, he said we needed GFI outlets where they already exist.
He said our closet light has a dangerous metal pull chain - It has no chain - it's connected to a switch.
Says my wife's bathroom has a noisy exhaust fan - it doesn't have a fan.
Says vents in my garage are covered - they are not.
In one paragraph, he says the door going upstairs is fire rated and self closes as it should.
In the next paragraph, he says it is not fire rated and needs to be replaced.
He wanted a self-closer installed on our garage door for spa safety. We have a gate between that door and the spa and the spa has locks on the cover.
In the course of his report, he recommends that the buyer seek expert advice from:
a grading contractor
drainage contractor
roofing contractor
plumber
pool contractor
electrician
structural engineer
mold inspector
HVAC cleaner
arborist
What exactly does he do for his $400?
Another inspector for another buyer later came up with a 20 page report and I could find only one error in it.