Until quite recently, when anyone in England opened his or her mouth and spoke, he or she branded him- or herself in terms of social class and local origin, and very unfairly, in terms of education. When i wrote something similar here a year or two ago, one of our English members stated that that is still true in England.
It is certainly true in "England" that a person's accent and vocabulary can give rise to assumptions by the hearer about the speaker's social and geographic background. Whether these assumptions are favourable or not depends on a number of factors, for example who is doing the listening and the nature of the conversation. A person who sounds like a toff might be perceived as trustworthy, intelligent and "one of us" or a stuck-up tosser. Likewise a person who speaks like a chav might be regarded as an ignorant oik or as a regular guy, a good person to advise on fixing the rear axle on my truck, etc. In between those two extremes you find a whole range of intermediate situations - people who speak like the BBC used to, who could have come from any class, people who use the "Estuary" or "Mockney" accents, blunt northerners, braw Scots, poetic Welsh folk, romantic Irish (southern) blunt Irish (Belfast), practical and businesslike Brummies, reassuring Geordies, etc etc. There are plenty (the vast majority as far as I can see) who are pragmatic and reserve judgement, preferring to wait and see. This is probably the thing has has happened "quite recently", if you can call the last 50 or 60 years "recent". Somebody who dismissed a person because of their accent would be perceived as ignorant and prejudiced in the same way as if they had dismissed that person for being black, Asian, Jewish or disabled, or for wearing glasses.
You will always have accents that identify people in terms of class and education. The country bumpkin, the sophisticated metropolitan. As I also know from my own observations that it happens in Belgium, France, Spain, Italy, Germany, Canada and the USA, I suspect that it must be fairly universal.