they should drop the facade and just say "We want you to work as hard as you can for what we pay you. that way we will value you more."
That doesn't seem true to me. Individual people might value a particular person they perceive as a hard worker more in a particular case. But then again, they might just want to sleep with you, or your sister, or play golf with you on the weekend, or whatever.
Corporations/companies, on the other hand, don't particularly need to value individual people working as hard as they can, since almost by definition, the system is set up so that any particular job can always be filled by someone else, and while training a new person might cost more than paying you a little more, this only goes so far, and doesn't go any distance if they can just shift personnel around internally to cover it. What they really want, if they're being honest, is for you to think you need to work as hard as you can, because you think then they'll value you more, but secretly for you to resent the job and quit before they have to go over a threshold of wage increases or collude to find reasons to fire you.