We may be conditioned to want rewards, but rewards can be attained through vastly different ways, depending on the individual
Also, we often want those rewards as a trade off for doing something we consider to be hard labour, in an area we fucking hate, in a job that sucks, so reward is largely required at present as a trade off for that. If you can take the 'i hate my job' aspect out of the equation, and people are encouraged to do jobs they actually have the natural aptitude for, or have a general interest in that particular sector (motor trade, environmental work, whatever ) , the notion of being rewarded doesn't hinge on money so much, and becomes more about not hating your surroundings and actively getting more intrinsic enjoyment out of your average day.
There's a huge amount of satisfaction to be had from knowing youre great at doing something someone else can't do so well, or from just working for a business that fits your political/ethical opinions etc