As a fellow immigrant working in the US and as someone working with non native speakers from other regions in the world, I can assure you this is not about racism. It is about team cohesion, clarity, getting things done in an international team. People have to spend extra brain cycles just to tune in to how you say things, before they can focus on what you actually say. This is especially true at the beginning of working with someone who's accent you have never heard. There is a big difference in accents between someone from India, France, Ukraine. While there is nothing wrong with that, it has value for international teams to mitigate this difference and settle on a common standard.
I like your point about cohesion. I'm not an immigrant here so, perhaps obviously, I agree. I have worked on teams and accents of those I have to collaborate with is a big factor in determining overall "friction". Often if the accent is too strong, it really makes the interaction dreadful because I (and others) want to understand you but it's difficult and embarrassing having to ask "what?" three times per sentence.
I don't think you need any better example than support call centers. How many people routinely avoid calling for support or simply loathe the idea of doing so because they're like to get someone with a heavy Indian, Filipino, etc. accent that leads to the scenario I mentioned above ("whats?")? When it comes down to it, it has a real cost in many ways.
