Will once again re-up the concept of a “right to root access”, to prevent big corps from pulling this bs over and over again: https://medhir.com/blog/right-to-root-access
But if anything, regular people should have more of the cake.
I.e. a warning would be if he didn't want it to happen, but my understanding is that he very much did.
And the people did rise up and successfully tried to fix the problem - there was a big socialdemocratic movement that culminated between the world wars.
What he underestimated was the ingenuity with which the capitalism reinvents itself (and creates new forms of private property to gobble up - free computing in RMS's sense just one example). He also overestimated ability of most people to understand the problem (it's lot more lack of emotional rather than intellectual capacity). I would say alienation is central to Marx, unfortunately alienated people can be so indoctrinated to fail to consider the alternatives. Most people seem to prefer to suffer through hardship rather than demand an alternative solution.