I can't say that anyone I know has ever actually believed this. The closest I've ever heard is "money is the only motivation for mercenaries," which isn't really the same thing.
I've also predominantly met people in my life who don't ascribe to this rule necessarily... but, that doesn't change the premise that the system we live in operates on it.
Most people for that matter within the current system have barely enough to live, let alone help anyone else.
How many people lost their homes and ended up on the streets due to insane debts that they could never pay off?
Or how many people in USA today are in debt to the banks or some other institution in some capacity?
The worlds economy is based on debt... which is how money is generated.
How does the USA plan to pay off its trillions large debt? Or any other country/nation for that matter?
Simple answer is... they can't - because they are blinded by the notion of 'money' and 'cost' so much that they can't see anything else besides it and think that more money is the answer (and we've seen how that turned out).
90% of the things ANYONE does are free. Take you, right now, reading this message. Are you getting paid to read forum posts or respond to them? Are you making any money typing your response? Did I make any money raising my son for the past three and a half years, and if I turn out to be a better father than my own, do I get a bonus in the end?
Of course not. But then... if I offered you a choice between posting on trekbbs for $3 an hour or mopping floors at WalMart for $20 an hour, and you can only pick one of the two, which one would you pick?
If I live in a socio-economic system where I have to have money in order to survive (let alone do anything else), I'd probably pick the higher paying option so I can ensure I have enough to live and maybe secure some kind of savings in the long run for other things.
That choice is a mere byproduct of a system I live in and doesn't demonstrate anything besides the premise that a person goes for the higher paid option simply because it offers more access than a lower paid option so they can ensure they don't have to worry about those things in the first place.
But... financially situated people... or even those who have their needs met already would probably pick the low paid option (posting on TrekBBS) or even do it for free - myself included (plus I've already done that).
If you eliminate money from the equation though completely and base an economy around access abundance and user-ship, if there's a need to mop a floor of a Wal-Mart for an hour or two, fine, I'd do it (and with high enough rotation of people, you'd only need to do it for a fraction of the time, which would take say an hour depending on the size needed to be cleaned) - even though it would be unnecessary since that can also be automated.
And as has been asked of you MANY times, what exactly do you propose we do with the laborers?
Consider the fact that not everyone in this world WANTS to spend half a decade in college just to be able to do something useful, and not everyone is mentally or psychologically capable of doing so. Not that anyone here is inclined to celebrate mediocrity, mind you, but denouncing it altogether can be even more hazardous.
The purpose of implementing automation to its maximum potential is to free people from the notion of being required to work so they are free to pursue whatever it is they want to do in life (which today is severely limited since you have to have 'money' in order to achieve that).
Re-education was just one possible alternative I mentioned - which if you would eliminate monetary based economics would be necessary because you cannot THROW people into a new system without informing them of it or how it functions, etc. (which is exactly why numerous problems are happening today - things change and people are thrown into new situations without being properly informed of how they work and are expected to 'adapt' without any sort of support from those who instigated those changes in the first place).
Travel for example is another option, or do your hobbies on a full-time basis - all the while not having to worry whether you have enough to eat or where will you sleep (because those notions would simply not be an issue).
To pose a question... are there things besides work in your life you expressed an interest in doing? Doesn't have to be re-education or travel.
People wouldn't waste away doing nothing. Majority of humans would go stir crazy (and those who do waste away today are doing so mostly because they don't have the purchasing power to do anything else).
We occupy our time even when we don't work (professionally) with something we find of relevance to us.
Even those who hang on the internet. They are constantly exposing themselves to new information and education in one form or another.
I'm not saying a change would be simple.
We are talking about a fundamental paradigm shift that also shouldn't be done 'over-night'.
One option on how to get there would be to for example... increase automation over the next 5 years to the level where people would be required of working 2 to 4 hours for 5 days in a week - without decreasing wages... and in the next 5 years, you further decrease the work hours.
That way, people get acclimated to changes and they start realizing the 'need' for work is not as big as they once thought.
With more time than ever at their disposal, they would be free to devote more time to things they might perceive of more importance.
In the meantime, expose those people (and others) to relevant general education.
Encourage critical thinking and problem solving.
Send soldiers back to school so they can learn how to bridge differences between nations - and not be killing machines.
There are tons of options to consider during the transitional period and what can be done (which would be a period that money is still used [approximately 10 years - maybe 15 to allow for sufficient social changes, even though we can transform the planet on a global basis to extremely high technological developed world in less than a decade]... just with ever decreasing emphasis until its completely phased out).