Author here. I get this counterpoint a lot and for good reason. My best response is that a resume isn't something you come up with on the fly. It's a document you have every opportunity to show to people, get feedback, and improve upon. Therefore, if you're not a native speaker, you should presumably have the self-awareness to mitigate that disadvantage by enlisting outside help.
I understand those arguments, but it doesn't addresses the issue for a very specific reason. What if the problem is the way internally the team works?
When measuring end-to-end, any part of that may influence the final outcome. If, and I am not saying this is true, if there is a tendency to have a few more errors (especially grammatical with it's its) in a non-native tongue, success outcomes MAY point to a bias in interviewing, or in how people interact internally.
Or not. It is just something I wondered, and something it doesn't seem like you've looked at specifically, and understandably as well, because who wants to open themselves to accusations of bias with their own data?
I opposed the connection between general grammar/spelling and what people do on the job. I'm a perfect example of it: informal writings are quite rebellious while professional ones are carefully written and revised. Because I'm paid to and misunderstandings cost more. :)
That said, I totally agree with your comment here that the preparation time available should render resumes free of such errors. They should be peer reviewed, as well. Problems caused by a lack of either indicate a character flaw to me.
