That's the key. What employer wants its clients/customers to repeat what they say to its employees? They can lose the client's business with the company that way.
For example, I am a deaf customer going to a store, I communicate to hearing people by writing so I write something down for an employee to read, then this employee can't read it (due to poor English reading skill, ie: Spanish or Asian speaking employees who can speak and/or understand English in voices but can't read English on a paper) so s/he gives it to someone else. That's a turn-off, isn't it? That's common in Southern Calif.