Humidity levels are all about the rate of moisture loss for hard cheeses, and rate of mold growth for cheeses with any sort of rind, including bloomy, washed, and other complex variations. The biggest aspect of most cheeses WRT humidity, IMHO, is that they don't lose too much moisture. If they do, you get a dry cheese or rind cracking.
Moisture levels in the cheese help to break up proteins and help with all sorts of other reactions that give cheese its flavor. More moist cheese matures faster. But other than that, so long as your rind stays in place so that molds don't infect the insides of the cheese, it should be ok. There's all sorts of ways to make tasty cheese
I tend to advocate controlled and exact environments to try and eliminate variables that make for poor quality. So I like to have the ability to control humidity. Sometimes it's necessary, like for bloomy rinds, you want it at a high level.