Why non-prevocalic /r/ and /æ/ are becoming more prevalent in ELF

I notice that more and more Europeans are starting to have rhotic accents. I also notice many of them use /æ/ for the BATH vowel. This is interesting because they are supposed to have been taught British pronunciation at school. Those two are notable features of American English. Not only I notice this among Europeans, even some Singaporeans and Malaysians are starting to manifest those features. Singaporean/Malaysian Englishes are traditionally non-rhotic, because they are British-based.

In sociolinguistics, many specialists hold that unmarked features prevail and marked ones eventually phased out when different dialects come in contact with each other. They also posit that regular features will win over irregular ones. Of course, this presupposes that all other things being equal.

So, it is understandable that why those two features mentioned above are prevailing. It makes more sense to pronounce the /r/ whenever there's an R in the spelling. Also, non-rhotic accents have complex rules on exceptions. This includes: the /r/ should be pronounced if the next word starts with a vowel; an /r/ should be inserted even if there is no R in the spelling, if a word ends with a vowel and the next word starts with another vowel, etc. It's too complicated for learners.  In the same way, using /æ/ both for TRAP and BATH vowel seems more straightforward, since both are spelled with the letter A.

There is even less reason to stick to the RP-type pronunciation, since almost half the people in the UK itself share those two features. For example, people in the north of England, Scotland and Ireland are mostly rhotic and have /æ/ for BATH.

If this is the case, why did non-rhotic and /ɑː/ came to be considered the prestige British pronunciation to be taught to foreigners, then? I think this is to do with prestige by dissociation. Groups set up linguistic rules that are difficult to master, unless you have spent a long time within this group. That's why in-group jargons are difficult for outsiders. In the same way, upper-class society in the southeast of England used those hard-to-master features as a "shibboleth" to distinguish themselves from the masses. Indeed, it's hard for an outsider to figure out why we should say pass with /ɑː/ and mass (Catholic liturgy) with /æ/!

But just because London happened to be the capital of the Empire, and people with power had such kind of accent, it was promoted as the standard, both within Britain and overseas. Later on, along with the social transformation, RP lost its prestige in Britain itself, but it was continued to be taught to foreigners because textbook writers and teachers needed an established standard.

The situation is somewhat similar to that of erhua rhoticization (兒化) in Beijing Mandarin. When to erhua and when not to erhua is quite arbitrary and difficult to learn unless you have grown up in Beijing. This is why people from Xi'an erhua practically everything, while in southern China, people omit erhua altogether.

By the way, the fact that English people are so conscious about the /ɑː/ - /æ/ issue proves that this difference does not affect intelligibility at all. All the more reason for us "foreigners" to adopt the one that is more regular!

In the international media, RP-type accent has become marked, too. So if  it's true that marked accents won't prevail, RP will likely not. Many foreigners and even Americans have positive attitude toward RP-like accents, because they associate them with imagined high-class British aristocracy and sexy men/women. Paradoxically, many sinister characters in Hollywood movies also tend to have a British accent. This shows exactly how "marked" RP has become in the American-dominated world of the media. It is used for a special effect, just because it is special. It is not plain and ordinary like the genetic American accent. So this means that few people will be putting on an RP-like accent if they are in serious or formal ELF situations, such as job interviews. On the other hand, those who can put on an RP-like accent may still be in demand for taping commercial messages that need to promote a posh image.