Thanks for the downvote because statistical facts on income apparently aren't your cup of tea.
Didn't downvote you, but you have heard the saying "Lies, damned lies, and statistics", haven't you? Calling a single chart "statistical facts" is laughable at best. Especially when we've seen two versions of that chart (see zaroth's post), with a near identical title (one has "US families", the other "US households") and claiming the same source data from the same blog, showing two very different plots. (Looking more carefully, the trends at least seem similar, so perhaps it is just an issue with the definition of "family" vs. "household"?)
Further, it's pretty clear that simply changing the brackets could result in a very different plot. And that is what we see in the NY Times article, which has the "households" plot but with the income brackets changed slightly and the 2009-2013 data added. In the NYTimes plot it looks like, since 2000, the top bracket has peaked and shrunk, the middle has continued to shrink, and the lower grew. It's a short trend compared to the full graph, but is that the direction we're heading now? So at best, this is all highly subjective, and a perfect example of when "statistical facts" can be manipulated to serve and agenda, populist or otherwise.
In short, nothing was "completely debunked" here, and a great example of why different sides of a debate end up talking past one another instead of acknowledging how complex these things can be. Two groups with different starting positions looked at the same or very similar plots and drew different conclusions. Color me shocked.
Even if it isn't, does that concentration of capital make the whole economic system less efficient than it otherwise could be or happens at the expense of basic living conditions for people in the (100-X)% group?