If capital allocation is a skill/talent like most other things, then we should expect to see some people consistently outperforming the general population (just as we would expect a professional basketball player to consistently outperform an average player). If this group of skilled capitalists consistently gets higher average rates of return, it seems inevitable that over time they would end up with a larger fraction of the wealth -- that's just math. I'm surprised that this is a controversial observation.
I don't know that it is. What is controversial seems to be what comes next. Do those capitalists get to use those fortunes to wield massive political power? Do they get to make rules that benefits themselves even to the detriment of the larger society? Do they get to leave their fortunes (and corresponding political clout) to their children, who may be far less talented?
I haven't read this book, and maybe this isn't really the question you were asking, but it seems like there is some confusion about why people like myself have problems with capitalism. I have no particular problem with smart people being rewarded to some extent for finding new ways to make life better for others (Adam Smith's baker making bread for the town not to feed the town but to enrich himself).
But I do have a very, very big problem with the idea that just because someone "won" the economic contest he or she is somehow fit to make social and political decisions or somehow deserves greater consideration in the social and political spheres. I also have a huge problem with inheritance, though I don't really see a non-"radical" way to solve it.
The (current) top comment says: In his recent book "Capital in the 21st Century", he's done something very big. He's pointed out that capitalism is flawed -- that inequality is not an unintended result, but rather an inherent feature of it.
So apparently the fact that capitalism naturally produces inequality _is_ controversial.
How to address that inequality is obviously a hard question. However, if you are thinking about it as "rewards", then you are guaranteed to arrive at the wrong answer.
what about his kids? what about retirement? The idea is that after having accumulated wealth, he doesn't need talent to continue accruing capital without talent. Because capital brings money faster than skill.
I don't know what you are asking. The skill I'm referring to is capital allocation, and the capital that is growing is necessarily invested in something other than a savings account.