And in the US, the inspector is typically only liable up to the cost of the inspection, or some pre-arranged value. He also isn't an actual engineer, so is mostly worthless. He'll check the roof with a pain of binoculars, but not necessarily get onto the roof. He'll check the age of appliances, but that's mostly obvious to anybody willing to do a base amount of research. Etc.
If there's anything remotely questionable, they'll punt and tell the buyer to hire an actual engineer (or plumber or electrician), so even more money out of pocket.
It's similar with the survey. In a mortgage survey, they basically verify that a house of the specified construction and square footage is on the property where it is supposed to be. Nothing you really couldn't see by just driving by.
When I have bought a house, in order to get a proper survey with the property boundaries marked by stakes I had to pay for that myself.
If there's anything remotely questionable, they'll punt and tell the buyer to hire an actual engineer (or plumber or electrician), so even more money out of pocket.