Comparing rafting to climbing Mount Everest is unreasonable.
Secondly, its not unreasonable at all. Sure the trip you may have done on vacation was an easy float down a class 3, but that's the equivalent of hiking a small hill an hour from your home. There are plenty of rafting expeditions that probably took way more planning and organisation and unknowns than some rich kid paying a million bucks for some company to hold their hand all the way up Everst.