As I mentioned in the comment below, this is the first excuse for such discrimination, as most of the times they do properly communicate and can effectively communicate the idea, but it’s the covert way of discriminating them. One of the examples I witnessed, someone was from Singapore -and in Singapore just like a lot of other countries, English IS native, i.e. taught early in life- but they do have a thick accents, and the candidate was eliminated because of that, and obviously the hiring manager made the same silly excuse like you so he can feel better about himself, that it will “hinder” the communications. As long as the communication can be conducted, anything else is pure linguistics bias, you don’t see such bias when an international team of scientists are working in a space station or similar projects for example, even though in a lot of cases they lack the vocabulary per se, and lacking such vocabulary did not indicate a lack of skill or intelligence either, let alone to be evaluated by an average IQ hiring manager.
Another case I witnessed was in Canada, where French is an official language, yet the hiring manager excluded one candidate because he had a thick French accent..
Technically speaking too, there’s nothing as “native English”, we all do have an accent to some degree, a lot of English vocabulary are taken from other languages, and even English speakers do have a lot of silly typos and mistakes in their writing all the time, including my writings in here, so it’s never an excuse.
>And speaking of discrimination, you wouldn't hire a paraplegic person as a nurse or firefighter, right?
That’s a poor analogy, you do have the tools to properly and easily compensate such linguistic disability, as easy as having someone double checking their writing or having one of these new AI spell check tools, etc., but we don’t have the proper technology and tools to compensate for a paraplegic to be a firefighter, yet, say in the future there are proven ex-skeletons that can help, then yes you are discriminating.