agreed. but (at my current job anyway), i'm paid to put a smile on my CTO's face each day, not make a decent product. very, very different goals.
Putting a smile on the CTO's face rather than producing something of value is arguably immoral. It's not producing what you're "supposed to" produce. (Whether it is actually immoral depends on how you define "supposed to", and what weight you give it.)
I think a better definition would be "giving up something intimate and precious for money" (beyond simply one's time and good humor). Or other words, giving up a significant piece of oneself (beyond simply a smile, or the fake-friendly vibe demanded by many work environments).
Putting a smile on the CTO's face rather than producing something of value is arguably immoral.
And this I disagree with you on also; however it's a purely subjective disagreement. (Arguably making people smile is producing something of value, if it smooths over bumps and helps them get through the day. But that's just how I see things).
BTW, I for one don't see prostitution as immoral (or any more immoral than, say, selling junk food); and it can even be legitimately therapeutic in some cases.