The general idea that anyone who contributes nothing should get nothing is widely held, and is a good starting point for socio-economic organisation but needs qualifying. Any work can theoretically be monetised, and anything that could make a profit is likely to be.
Yet society has changed and it is generally accepted that the very young, very old, very ill and very disabled, amogst others, should not be expected to work except perhaps in a very limited way.
Society has also decided that certain kinds of work are not acceptable to society. For example selling drugs that have been made illegal and solicting (prostitution). And certain consumption is limited, and or tolerated but not encouraged: smoking products and alcohol are age-restricted.
I would say there is a general consensus that society (however it is incorporated) can and should place limits on the pure profit motive. There is less consensus on what the nature and extent of those limits should be, but that there should be limits is widely accepted.
Turning this 'limitation consensus' on its head, we find, surely, that we are testing to what end people are working. Is what they do a contribution to society? It cannot be the case that any work will do. Many things that are destructive of property or life and limb are constrained to varying extent by varying mechanisms from social pressure to the full force of the law.
In the current political environment, the assumption is that paid work should ideally be in the private sector - that is not directly funded by taxation. The test doesn't seem to be to what end the work is being done so much as whether there's financial profit to be made. The assumption seems to be that the money made through profit will eventually yield up benefits, perhaps even social benefits.
Traditionally the public sector delivers services that society collectively wants to see delivered - it expresses this desire, theoretically, through the democratic process. Since the late 20C there has increasingly been a strategy of using private sector organosations to deliver these collectively-desired social benefits.
But the private sector exists to make money, in the main, and the owner / employee model prevails. People are expected to work for a living, preferably in the private sector, and it is that same private sector that according to currently prevalent ideology is best placed as well as preferable to provide the employment. This gives greater control over what is done by way of paid work to the owners of the private sector organisations, who thus have more influence over what ends the work they pay for achieves.
This leaves the individual with a dilemma: s/he cannot decide what is socially desirable or constructive and then use her/his labour of hand and brain to do that. S/he is limited to a large extent to doing what the private sector decides it wants to pay wages for. And not only that, if the private sector changes its mind about the amount and types of work it will pay for, people can instantly be out of work and deemed a drain on society.
Further, the amount of that needs to be done by humans is decreasing, as automation prevails. The effect of this has to be most felt on those without the skills to carry out the remaining non automated jobs, which is a problem for them if they are still expected to work for a living and do not have independent means. What is it they should do?
What is the essential difference between those who it is generally accepted should not be expected to work to live and those who do not have the skills/abilities to do the non-automated work that has been deemed necessary and/or desirable? I think there is only a difference of degree. Obviously people cannot only carry out work beyond the limit of their capability, but how do we determine what work is necessary and socially desirable, and how do we share out the work amongst those who can do it?
If we look at what is generally deemed socially unacceptabe - say dealing in illegal drugs - we can see what the determinants of that unacceptability are. The drugs have been made illegal (ostensibly at least) because of the profound effect they could have on the user, especially with continued use. So society has deemed itself worthy of protecting people from an activity that is profitable and involves work. This seems to be to show that it is in fact human well being that emerges as the end of socio-economic organisation. The question is why it isn't in every case, but only in the extremes.
If the intention of our socio-economic system is to improve human well-being, then money has to play a part in this, and not work against it. And having less work to do must surely benefit human well being (setting aside the personal fulfilment element of work). This is why an RBE makes sense to me. It aims to improve human well being whilst conserving resources.