People would far rather argue over politics than solve problems. They like buzzwords better than facts. They favor short-term thinking over long-term thinking. (Some communist countries have worked in terms of five-year plans, with varying degrees of success. That was about as far as they could get. Most others do worse.) They pursue personal gain at the cost of others, even if the pervasive impact winds up personally detrimental. They persist in believing that they can steal the cheese without triggering the trap. Hence the annals of history scattered with the wreckage of crashed civilizations.
Every economic or governmental system humans can devise has been flawed, because they all have humans in them, and humans can turn pesky. But if people would frigging well stop arguing and examine the results, it would be possible to identify which techniques work better and which fail horribly, then assemble the best pieces to counterbalance the worst. Keep doing that and it will eventually produce a system that works pretty well most of the time. We've had some progress; democracy was a good idea because it spread out the power over a wider area, such that more people had to be stupid simultaneously rather than just one or a few. Actually some of the failures we're seeing now are because the power has once again been concentrated in too few hands while a majority of America is prudently screaming, "We need JOBS, you rich imbeciles!"
If you want to know what's going on, ignore the arguing and look for facts. What is predicted, and what actually happens? Claims of "trickle down" economy do not match the data, for instance, because financial records show that America's wealth has overwhelmingly been sucked upwards in recent decades. Look at some of the major economic models and see how their descriptions match or do not match observed performance. Knowing the source of the problems privately won't solve them, but can inform better decisions as to surviving other people's mistakes.
Some of the online discussions about the interview:
Roubini: Marx was right. Capitalism may be destroying itself.
Marx was right; capitalism can destroy itself: Roubini
Is Nouriel Roubini Saying Capitalism Is Destroying Itself?