This video interview is very interesting, but it is almost entirely about the problems of capitalism, which I agree are very real. It says relatively little of the challenges of making socialism or Marxism work. I didn't hear the speaker directly articulate this, but Marxism, aka communism, is basically socialism (an economic system contrasted from capitalism) coupled with a political strategy of revolution intended to install that socialism.
I think capitalism's strength and socialism's weakness is the former's strong incentives to reward innovation that lead to advances in productivity and technological advances. The converse is that the wealth generated, unless some counterbalancing force is applied, will inevitably become more and more concentrated into fewer and fewer hands. Capitalism is a giant game of Monopoly. Almost everyone loses in the end, except for the lucky (and/or ruthless) overlords.
Personally, I am fascinated with the political aspects, as distinct from the economic ones. In my personal idealized world, socialism and capitalism would be nicely balanced, as HeathenFarmer suggests, with socialist systems providing a social safety net for key provisions of healthcare, education, civil defense, environmental stewardship and disaster relief, housing and food and childcare support; in other words, with those provisions in place, poverty per se no longer threatens individuals so much. At the same time, capitalist opportunities could still reward individuals for being creative and industrious, providing motivation for advancements in applied science.
As for communist revolution, it has never seemed to solve the problem of how to prevent power-hungry strongmen from seizing political power and using it to benefit themselves and their cronies at the expense of the masses. Call me a democratic socialist sympathizer! But I still think revolution begets further instability. I prefer incremental implementation of socially responsible socialist steps.

I think the key is to strike a balance between the 3 "isms".