This is just wrong. I really hate it when a writer "teaches" other people what they "don't know", by publishing a treatise about something they don't understand themselves. This author does not know what capitalism is.
Capitalism is simply the private, as opposed to public or government, ownership of the means of production. A blacksmith in the 1700s who owned his own shop and tools, and then sold his products and kept the revenue, was a capitalist. A psychiatrist with her own business is a capitalist. Capitalism absolutely applies to small mom-and-pop enterprises.
Capitalism takes many forms, from perfect competition with many small producers, to monopolies of one or oligopolies of a few producers. Greatly different outcomes, but the same overgeneralized economic system. Note that in the model of perfect competition, industry profits tend to zero in the long run.
Capitalism is not defined by corporations. Large corporations reporting to shareholders is indeed a recent phenomenon, but that does not define capitalism, it is one form, you could call it "corporate capitalism", but it is most accurately described as "monopoly capitalism", in which the corporation can set the prices of its products and does so to maximize profit.
The problem that we face with corporate capitalism is the monopoly part combined with "free" markets. Rent-seeking behavior, if there were no controls at all, would tend any capitalist economy toward a single producer. The term "free market" means the absence of any such controls. And, yes, the free marketers are winning, and our markets are becoming increasingly concentrated, and that has greatly distorted our economy toward becoming a dichotomy of billionaires and paupers.
In addition, our economy is a mixture of capitalism and socialism, as is every country in the world, save maybe Cuba and North Korea. The policies that could change our economic system to benefit the majority of Americans should be the right level of controls to make capitalism work better, along with a better array of social guarantees. With the right mix, capitalism could shine as the most efficient means of organizing production.
So, Umair, you are in the category in your title, one who does not understand what capitalism is.