Hmm....very good point.
I believe there is also Singaporean English, and Singaporean
English can be put at the same level as American English.
But Singaporean English is not necessarily Singlish, it just
differs from the choice of words, the expressions, etc, so it is
still formal English but with Singaporean characteristics.
Yes, that is what I'm talking about. You know, Singlish is
considered a screwed up corruption of the English language, but
American English is not thought of as such.