At that time, there weren't enough qualified RP teachers around, maybe even in Southern England, to teach pronunciation as a subject in its own right, even if you studied English at "A" level.
Phonetics has been taught at university level since the days of Henry Sweet and Daniel Jones. Pronunciation/Elocution probably has a longer history - think of
Pygmalion/My Fair Lady. My present, roughly RP, accent is in part due to the 'how now brown cow' drills (I'm serious!) that began at my prep school in 1954-55
I've not lived "up North" (Yorkshire/Lancashire) since the early 60's and have had not used RP, as such, in the multinational/multicultural oil/gas/petrochemical industries in the UK or abroad. I try to stick to plain English that most people can understand.
There are many very successful English (I deliberately use that word rather than 'British') people who do not speak RP, and no serious linguist considers non-RP varieties in any way inferior. It is, however a fact (regrettable in my opinion) that for many years RP and similar southern British 'educated' varieties of English were, within England at least, considered to be a sign of intellectual superiority.
While listening materials provided with most modern course books do use speakers of other varieties of English, they mostly avoid the 'stronger' dialects, and the bulk of the listening material is roughly 'educated' southern English. As a result, many learners believe that RP and similar varieties are 'standard' British English, and they have genuine difficulties in understanding speakers of other varieties.
I [...] can't generate an "ng" in "bank" although there's always one in Bangkok. My "in" is the same, whether with London or Cardiff.
As I can't hear you speak, I'll have to take your word on that, but I have to say that you must be in a tiny minority of native speakers. When I was taking the phonology part of a Cert TESOL course, many of my native-speaker trainees denied emphatically that they used /ŋ/ in 'bank' or 'in Cardiff' (or that they pronounced 'handbag' as /hæ
mbæg/). Indeed, when they demonstrated the words/phrases to prove their point, they didn't, because they were thinking about what they were saying. I spent some time setting up situations in which they uttered the words without thinking, and eleven fellow trainees and/or my recorder testified that they did produce sounds that they claimed they didn't.
My primary interest in the English language (as you may have noticed) is in the tense system of English. However, during my time as a teacher trainer, I spent a lot of my spare time on phonetics/phonology - largely because I was appalled at the bilge my trainees were presenting to their students. I have had trainee teachers insist that in an utterance such as 'I think he's coming tomorrow', the
h of
he's must be clearly produced. Not to produce a clear /h/ is to
drop your aitches, a clear sign of lack of education. Sphericals! 95+% of people from England do not produce a clear /h/ in such utterances in normal conversation. I doubt if many speakers of most other varieties of English do either.
I have to admit that I am on one of my
hobby-horses. I honestly don't care what method (grammar-translation, direct, audio-lingual, communicative, etc) a teacher uses, so long as the learner is enabled to communicate in English. I believe
passionately that teachers, however they enable learning, must, in order to be able to do this, have a clear understanding themselves of the grammar of English and of the way in which native speakers actually produce the sounds of English.
Time to stop, I'm getting warm.