If people "choose" to work rather than "need" to work, then only some of them would CHOOSE to work. The other would prefer to enjoy the luxury life and become unemployed.
Yeah, probably. So?
I think what Brainsucker may not take into consideration that civilization as we know it... especially for a technologically developed age as we live in today, requires VERY FEW people to actually work and drive technology forward at faster rates - because most jobs are unproductive to society as is and only serve to 'move money around' for the sake of monetary based economy - actual production is automated/mechanized to a large degree (and we can automate so much more with existing technology alone).
Besides, the notion that 'most people would simply choose to live a luxury life' is an assumption without basis.
It depends on the environment.
If you simply transposed people from an existing system to a non-monetary one without exposing people to relevant general education, informing them of sustainability or how it all works, you will end up with the same problems we have today.
There is a reward, just not material one. There is acclaim and appreciation of the society, the exitement and feeling of accomplishement.
To me this doesn't seem like a hard thing to grasp. Material rewards have been all of the human history just one of the many motivations for doing things.
'Rewards' - if people really need to look at life like that - could be seen as a sense of accomplishment.
The realization you completed a task using your knowledge/skills to help others (for example).
I did this on many occasions without asking for money or compensation of any kind.
Money was demonstrated to be ineffective and cause a detrimental effect on people when they needed to actually think, use creativity, and problem-solving skills.