as long as it's in the contract, it's not a problem.
Insruance companies should be able to practice not paying out for dumbass behavior so the other people that think about what they do don't have to pay for the morons.
The problem is what one person thinks is "dumbass" behavior may not be to someone else. You could probably find something risky that I do that I don't consider unsafe. I could probably do the same for you. Seems to me that insurance companies would love this and not have to pay for much anymore. JMO