We don't have to litigate this from first principles; this is such a common problem that there is a name for it in EEOC circles: "accent discrimination". You can be civilly liable if you do it.
Under Title VII, an employment decision may legitimately be based on an individual's accent if the accent "interferes materially with job performance." To meet this standard, an employer must provide evidence showing that: (1) effective spoken communication in English is required to perform job duties; and (2) the individual's accent materially interferes with his or her ability to communicate in spoken English. [1]
[1] https://www.eeoc.gov/laws/guidance/national-origin-guidance....
(1) Programmers need to be able to communicate about what they did, what they need to do, and how things are designed. (2) Interviewers kept on saying things like, "I managed to pick out enough of the right words that he probably answered me, but I wasn't sure."
None of us cared that he had an accent - we hired plenty of people with accents. We cared that we could not understand him well enough to coordinate with him. But if we had told him that, he would have had grounds to file a lawsuit. We'd have hopefully won, but he could still file it.
Speaking personally, if the company hired an interpreter, I would have been OK with it. If the company insisted on having all design meetings in a chat room, I would think that crazy. Most people's typing speed is a small fraction of their speaking speed.
You're referring to the Americans with Disability Act. What it requires depends on the "essential duties of the job" and what is consider a "reasonable accommodation". Those are judgement calls. Those judgement calls need to be made by executives on the advice of HR.
My lay understanding is that the law does not insist that the job requirements change. So if being able to participate in design meetings, daily scrum, and so on are daily requirements for anyone to have a programming job at your organization, they are essential duties. Even if the same job title in another organization has different requirements. (But can you document your requirements?)
That brings us to the question of what a reasonable accommodation might be. Hiring a full time interpreter to follow that person around is probably considered unreasonable. Allowing someone who lip reads a device that can do text to speech is clearly reasonable.
The ADA affects the decision. But it doesn't make it for you.
Also: if your management decided to exclude deaf people from your team, wouldn't you quit? I would quit.
As for protesting choices that you don't like by quitting, that is your right. Speaking personally, deciding not to hire someone because you believe that they will be unproductive in that role seems to me to be a perfectly reasonable thing for a business to do. And I don't see a moral distinction between different reasons why someone is expected to be unproductive.
These are, of course, just examples from a complete non-expert, and there is a plethora of information on the Internet regarding accomodations, as well as what's considered reasonable (and how that's arrived at for each situation).
Even if a heavy-enough accent could be accomodated in a similar manner (which is debatable, at least), it's questionable if it's a disability under the law (philosophically/morally is yet another matter).
Anybody can file a lawsuit against anyone else at any time for any reason.
I think the reality is that credible lawsuit threats will virtually always settle, relatively quickly. That's what I've seen at smaller companies, and I assume it's even more the case where Ben Tilly works.
Did it ever occur to them to ask "Sorry, could you repeat that?"
Sometimes it takes a bit more effort to understand someone, whether it's because of an accent or a speech disorder or whatever. As an interviewer, you're in a position of power, and you have an obligation to put in that effort.
But even if i do successfully communicate with such a candidate enough to evaluate them technically, i will most certainly bring it up during the debrief. To not do so would be dishonest and unprofessional; i cannot make a call that it would be ok to hire this individual under an assumption that all communication will be written or whatever.
Also, it is very probable that i will have only managed to make it through a small fraction of my intended questions in such a situation.
(I have to say that your assumption seems unwarranted that the previous poster was simply not bothering to ask them to repeat themselves.)
So the intent of the law is to prohibit making hiring decisions on the grounds of "I don't like that particular accent", it's not intended to force companies to disregard whether a candidate is intelligible.
Seems sensible enough. I imagine this isn't even specific to foreign candidates - here in the UK, there are quite strong associations with different regional accents (which ones sound 'refined' or 'unrefined', etc). It would of course be unfairly discriminatory to rule out a candidate on those grounds.