I think musical snobbery does exist, but perhaps not in the way that has been expressed above.
The musical snobs, to me, are those who like only opera, or classical music, and seek to make them their exclusive property, considering the bulk of their fellow humans unfit to be allowed into their territory.
We've all seen them! The dinner suited, pretentious purchasers of £80 seats at the Royal Opera House or the Albert Hall.
The antithesis of those with a genuine love of the music for its own sake, who inhabit events like last night of the Proms.
They are analogous to the wine snob, who is only interested in the greatest and most expensive vintages, forgetting the fact that the only decent wine is the one the taste of which you most enjoy, whether it cost £100, or £5 per bottle.