It's really not about "not hearing opposing views", it's about gay people not wanting to be called fags, black people not wanting to be called niggers, Asian people not wanting to be called chinks, women not wanting to be told to get back in the kitchen, etc. At least, that's what the movement is at its very core. I think there's this big assumption that such is what "tolerance" is. There's certain opinions that one doesn't want to espouse in a tolerant, safe environment, but beyond that...
Now, I agree that in practice some people take things too far.
But I also agree that if the Nazis want a space on campus, the Nazis should be able to lease a space on campus. Do I think they should be able to do it without being protested? Of course not, but the door swings both ways.