I call it the Laura Norder phenonmenon.

Based on experience in life and on several forums (esp. BBC Radio 4's Word of Mouth), I have come have the following "totally unscientific personal opinions/assumptions". NB: In no way, am I saying that this is factual, it is just a personal opinion that I built up over time and limited specific observations.

1) Americans are taught that their local dialects/pronunciations are wrong, shameful, etc. I consider this in many ways to be a bad thing, except...

1a) Most Americans regardless of how "oddly" they pronounce a word, will agree (to some extent) on what the "standard" pronunciation(s) is(are), what it rhymes with, and if asked to write it phonetically would come up with something similar. My father (when speaking naturally) says "go 'round the carner to put out the far", but he would be embarassed if you pointed out that he had not said corner and fire and would never say that there is an ah sound in either.

1b) It possible to have a semi-reasonable discussion of pronunciation among most Americans where you can at least agree on what you disagree about.

2) British people are taught that their local dialects/pronunciations are something to be proud of, which in many ways is a good thing, except...

2a) Some (few?) British people will defend to the death that their local one is the correct standard and will not allow the existence of difference yet, much like the Red Queen, insist that everyone else's dialect is also correct.

2b) Some (few?) British people are very difficult to discuss pronunciation with as it is their way or the highway even if they agree that a difference could exist but only "in theory". For example:
2b) i) Law and lore rhyme and should be written the same phonetically - lor. (hence law and order becomes Laura Norder)
2b) ii) The sound represented by schwa has an r as an integral part of it, i.e. the R-colored vowel (aka schwer) is not schwa and a hint of r sound - it is schwa itself! (It was the presenter of the program who is a professor of English who insisted on this point.)