I disagree. It's exploitive for people in a position of power to exploit the psychology of the folks that are in their care. You use the word exploit, exploiting folks isn't good or moral, in any case. It's never ok to exploit folks.
If we say we are aligning the interests of the employer and employee that's different. If we are saying a rising tide raises all ships, we all do well when we all do well, etc. That's different. None of that is exploitive, it's inspiring. There is a difference between inspiring and aligning people in powerful ways, and exploiting them. One is ok, one is not. One leads to true long term success and prosperity, one leads to short term success but long term failure, a flash in the pan.
I was admittedly being facetious, but my point is that those who push the "work is for working, not for having fun" line are neither doing the employers nor the employees any favours.
The other side of the coin is that what employers do to try to improve engagement is usually ineffective and often quite demeaning. What Erik Dietrich calls "carnival cash". You just can't fake the sense of producing something useful for the customers and in return getting your fair share of the proceeds.