The above quotation comes from the esteemed mind of W.E.B. DuBois, and clearly speaks to the fact that capitalism without the powerful enforcement of vigorous governmental rules and regulations, as well as appropriate taxation enforced upon those that have more than enough money to buy the taxman, will not ever bring forth the type of society, that makes for human inclusiveness and the caring for the good of one another.
To somehow believe in trickle-down economics and other insipid lies along this line, are going to somehow be beneficial on some level to all the people that make up this land, is a delusion, which nobody with any sensibility should ever believe in. Indeed, those who have money and/or make good money have a very strong tendency to desire to keep as much as they can or to invest such to make even more, and though they may well have an interest in doing their part to bring forth social good, that typically isn't going to be their prime interest, at all.
It has to be said, that there are plenty of people that believe that because they earned it, or they have it, that they then should not be compelled to give up much or any of it because they feel that what they have is theirs, and fairly theirs. So then, in consideration, that there are only so many pieces that a pie can be divided into, those who are reluctant to give up any of theirs, reflect that other people are going to come up with the short stick, time and time again.
So too, any time that an economic system is structured around winners and losers in what is principally a zero-sum game, which seems structured to downplay collaboration and cooperation, then the game is going to favor those that are well-positioned, clever, ruthless, determined, and selfish, over those that aren't as well prepared, aren't motivated primarily about money, and don't find that competition should be the be-all and end-all of our existence, at all.
A far better and a far healthier society is going to be one in which while there will still be rich people, they won't be insanely rich – and while there will still be poor and helpless people, they won't be so poor and helpless that they won't have a safety net to be there as an ever-present help in danger. What we should desire as a people is to see more people, simply have the accouterments that make for a good and stable life, of a good job, with decent pay, and a nice home, in a safe area, along with the infrastructure that consists of good schools, and social inclusiveness.
In any nation, in which the abiding interest of those that are the elites, is to “lord it over others,” then this is not going to produce a healthy and stable society, because that type of domination, necessitates the structure of governance exclusively favoring those elites, over the people, which reflects thereby that this is not the land of the free and fair opportunity for all, but rather this nation's governance is clearly own by the few at the expense of the many.