Idaho is a very rural state. Most of the population is in Boise, but every district in the state has a representative. This means that the wills of the city goers can't overrule the wills of the larger state as a whole, even thought it has the majority of the population.
Now, something to know about rural America is that it tends tomostly care about two things -- religion and the right to bear arms (this is a generalization, of course). As a result, the elected officials typically campaign on those points, and everything else is glassed over. Thusly, many of the elected officials serve special interest groups under the guise of a bible and a gun, and the rest doesn't really matter. It's not lack of intelligence, but lack or priorities other than these.
And that's how Idaho residents put up with these types of laws being put in place.