The problem is that humans are really bad at caring for unproductive people. If you use wealth generated by natural resources as a proxy for wealth generated by robot labor, humans have a bad record of distributing the material wealth.

Thank you for including those links. I especially liked this part of the conclusion:

So the transformation from capitalism to socialism requires political action by the working class, in order that it can establish structures necessary for the transition to socialism. Just as the merchant class during feudalism could discern its long-range interests in the full realization of factory production, the working class must discern its interest in the full emancipatory implications of automated industry. And just as the merchant class became a revolutionary bourgeoisie, the working class must become a revolutionary class that acts politically to establish a new type of society on a foundation of automated industry.

If anyone is curious, it's a short read and a good overview.