I'd never put a knife through what knifetests.com does, I view it as something kind of like crash-testing a car. I don't intend to crash a car into a concrete wall, but the tests are designed to show you want happens if you accidently do so.
Knifetests.com calls their tests "destruction" tests. kc2ixe recently posted about a job he had in "environmental testing." It pretty much seemed to be trying things out to see if you could break them.
Knifetests.com take a knife and puts it knife through a bunch of crap to see how it takes the punishment, and in the end, the knife is probably going destroyed. Destruction testing an item may have some benefit, but it is not the end all and be all. Look at the tests, and take it for what you think it's worth. If you think they are worthless, don't look at them.