I've gotten lots of emails from bosses and bosses' bosses like "i semt the file,pls confirm." Few seem to care about writing well in the workplace. With psychological things like how talking like someone makes them like you more, I wouldn't be surprised if "proper" writing was a hinderance to career advancement in such a scenario.
That may not be a counter-argument, it's quite possible that upper-level management doesn't feel the need to impress 'the little people', and only sweats over documents that will be read by their peers.
