I won't go into any depth because that is obviously not what the author had in mind here, but he is quite correct that one may see in the Manifesto the flaws that eventually shatter this system of thought. If I might borrow some terminology from systems analysis, Marxism is a wonderful descriptive model, allowing the student insights into some of the workings of society that were not well illuminated prior to the mid-19th century. But as a predictive model it fails. Items clearly stated in the Manifesto such as increasing illiteracy of the proletariat, increasing poverty, increasing "alienation," concentration of wealth away from the bourgeoisie into the hands of the capitalists, etc, etc, simply never came to pass and had to be heavily redacted between the 1848 Communist Manifesto and the time Marx came to write Capital in the 1860's.
As a normative model Marxism is truly disastrous, which is to be expected given its failure as a predictive model. The economic results of every single implementation of this in the real world were uniformly stagnant, unimaginative, and uncompetitive. It is no wonder that they had to build walls to keep people in. The model failed, obviously, spectacularly, and completely.
This goes on through each of the fields mentioned above. Marxist class analysis failed to predict the rise of the proletariat into petit bourgeoisie status, its increasing literacy, and its eventual participation in capitalism as an equal partner - the working man in the U.S., for example, is the number one owner of capital in the form of union retirement funds. One can't even call him a proletarian anymore and never really could. Marxist historiography failed to explain the evolution of government into representative form. Marxist management failed completely - Lenin ended the workers' soviets in 1921. Marxist politics came to rely on bigger and bigger lies until even its own most credulous citizens became cynical and apathetic. Marxist philosophy became bloated, jargon-paralyzed and utterly incomprehensible. It goes on and on.
But I probably shouldn't...
But as a predictive model it [Marxism] fails.
Fails miserably.
As a normative model Marxism is truly disastrous, which is to be expected given its failure as a predictive model
Marxist class analysis failed to predict the rise of the proletariat into petit bourgeoisie status,...for example, [the working man] is the number one owner of capital in the form of union retirement funds. One can't even call him a proletarian anymore and never really could. Marxist historiography failed to explain the evolution.
On the last point, I don't think Marx considered labor unions nothing more than a means to an end. But Marx was a European, with a European view of the world. To Marx, labor was only a commodity to eventually enslave to the state. Communism was simply a feudal economic model with industry as its core rather than agriculture. In the US, labor was the individuals right to withhold, either individually or collectively. The Unions in the US were the eventual foil of the communists, both here and abroad as in the case of Poland.
What irony! It was the communist influence in the Screen Actors Guild that prompted Ronald Reagan to become politically active, in the end, it was another union, Solidarity, that Reagan and the Pope used to bring down the Soviet Union.