It all comes down to the human tendency to divide people into “like me” and “not like me”. Shared artistic tastes are a quick & dirty way to estimate how much you have in common with someone, and there are a lot of people out there who look down on those who are not like them.
Are they really snobs? I don’t see why not.
I haven’t bothered picking it up because I’ve just never been wild about Celtic Frost, but so far I have yet to see a neutral opinion. Everyone seems to either love it or hate it.