Someone has probably already said this, so apologies if I am repeating things. Regional acents have roots that lie in earlier forms of English - they don't represent a 'fall from grace', they represent a different starting point. The different dialects of English have roots in forms of English that were often not mutually comprehensible, from the times when what we now call England (and a fair bit of Scotland) was divided up into several different kingdoms.
RP is an accent, not a dialect, and is relatively recent. It developed from the East Midlands accent in the 15th century. The East Midlands accent was associated with the centres of learning - Oxford and Cambridge, and was associated with London, the capital, so it gained prestige, but it didn't gain the (lessening) prestige is has now until the end of the 18th century.
It's just another accent. In earlier periods, different parts of Britain were the centres of power, particularly the Kingdom of Northumbria that contained the East Yorkshire ports, the great cathedral of Durham, and stretched a fair way into Scotland. If it hadn't fallen, we might well be seeing Geordie as the 'best' way to speak.
Is it snobbish to prefer RP? Probably, but more importantly, it suggests someone who is deeply ill-informed about the history and development of the English Language.