I've always taken a much different approach based on an entirely different distinction:
c) The writer who is honest with clients about his/her nationality & native language fluency; and
d) The writer who is dishonest about either or both.
I have no problem with "c" regardless of nationality or ESL status. But the client is entitled to make a fully informed choice without being deceived.
Let there be no doubt: majority of ESL writers are unqualified to write any research paper in the English language due to linguistic incompetence just as majority of native speakers are unqualified to write any research paper due to their technical/research incompetence.
Ironically. (given the chosen title of this thread), that argument is based on a fundamental logical flaw: namely, that "
if some A are not C, then all B must be C." (A=Native Speakers; B=ESL Writers; C=Good Academic Writers). It presumes that there's necessarily something about
just being ESL that automatically means ESLs all research and argue better than their American counterparts and that they automatically fulfill all the other criteria for being good academic writers. Quite obviously, that's not true.
In fact, from my experience, most of American 'professional` writers simply produce nicely written, grammatically correct papers that painfully lack substance/depth/critical analysis.
Considering that the whole argument about "ESL vs NS" is mainly of concern only to American students attending American colleges, your point would seem to be moot, even assuming it's true for sake of argument. Your argument also seems to ignore the fact that if American students are given the choice between an essay that "only" meets American educational standards but reads and
sounds like it was written by an American and an essay that meets "higher" educational standards but reads and
sounds like it was obviously not written by an American, they would prefer the latter. I'd reject that presumption completely.
Similarly, since there is a difference between the academic standards in the US and the UK, American-educated writers have the same obligation not to try to pretend to be UK-educated. I've lost (or declined outright) plenty of UK work and I'm always more hesitant to take advanced UK work for that reason and I've never tried to argue that a UK customer "shouldn't care" where I was educated or that all that matters is that I'm an English NS. Clients (everywhere) have the right to decide for themselves what criteria they want in a writer. The vast majority of American customers care at least as much if not more about language fluency and a native sound as they do about the depth and critical quality of the work. I'm not suggesting that either is more important than the other, just that it's always the customer's right to make that decision with all the facts presented honestly by any writer offering his services.
My point is fairly simple: A qualified, professional writer should possess these MANDATORY skills.
Without disagreeing with anything on that list I'd simply like to add two other criteria to your list of requirements while also suggesting that
failing to meet any of the criterion (including mine) never means that any writer necessarily meets any (let alone
all) of the others:
g) written language fluency in any language in which work is being produced; and
h) complete honesty in answering any questions from prospective clients, whether or not the writer happens to agree that the answer to those questions "should matter to the client.