If you go a step further, a truly racist company is never going to hire someone of a race they look down on, but they can't put anything on a job description about it, so they just end up wasting a minority's time.
- peoples accent improves in the first months of them practicing (with you).
- my understanding of non-native English speaker (Thai, Japanese, Indian, Chinese, etc) improved in weeks of exposure.
So I don't think anti-discrimination laws are harmful. The situation may not be as confortable for a few weeks but eventually it does not get on the way of productivity.
edit: added my native language, French
They also waste their own time, so there's some good coming out of it.
But I wouldn't say unintelligible accent is racism. I've met some unintelligible people that were born and raised where I live.
An accent is also something you can change (even though it's hard). So it would be really valuable feedback to the person who's not getting it.
I can usually predict quite well who will hire me based on my interview experience, but I've been surprised some times where I got hired after I thought I failed completely at the interview. This may sound weird, but in that case I usually assume the company couldn't find anybody else, which is also a red flag for me.
It may not be obvious to the other party that you didn't understand depending how well you covered.