Some manager who probably doesn't speak much English has tasked a random person on their staff who went to college in the US or UK with writing their English copy, without realizing the difference between "this person can communicate effectively 1:1 in English" and "this person can write formal English like a native speaker".
In other words, a task is being supervised by someone who doesn't understand the task. Just like every other company we deal with. As native (or at least highly fluent) speakers, we just happen to be competent to critique it.