Well, in discussing capitalism saying what it has done in the past will only go so far to defend the status quo. And past instances of Marxism, or likely Marxism generally won't suffice as replacements.
The main failures of 20th century communism was it was run by totalitarian governments & the economy was centrally planned by the government. Marx wanted a "dictatorship of the proletariat" but all people got was a dictatorship of some communist government elites to replace control by bourgeoisie elites , and the proletariat had control of almost nothing, even far less control than in capitalism or liberal democracy.
So a new system of Marxism needs to be a true dictatorship of the proletariat, which is democratic and the workers control most everything in the economy, not the government. Maybe Democratic Socialism could work, who knows. The problem I have with the article is it criticizes capitalism but says virtually nothing about how Democratic Socialism is going to solve our problems. I need details, I need high-level economic plans, not pie-in-the-sky naive hopeful utopian BS the far left is so often guilty of.
You acknowledge that there are drawbacks, so the conversation can begin. The 'new system' has to be new, also, that it recognizes that any new system isn't good just because it's "new". See Proportional Rep voting.
Exactly, see above. An ideal system would take the good parts of capitalism and remove/change/reverse the negative parts, as much as it can be done.