Let take a brief detour into how I see the historical emergence of capitalism. Keep in mind that I'm not an historian.
It should be no surprise that capitalism and the industrial revolution go hand in hand. Before both, the physical and technological means of production was human- and animal-powered peasant agriculture and crafts. These physical means of production had the following characteristics: Labor did not produce much of a surplus: the cost of a day's labor power was about one day's labor. It was difficult to exchange the products of labor both in quantity and over time and space. Mostly, people produced food, which (absent modern storage and preservation technology) spoiled relatively quickly if not consumed. And whatever surpluses could be generated and exchanged could not be employed — because we lacked the technology and knowledge — to improve efficiency.
The means of production do not strictly determine economic and social relations, but they do constrain them, and act as a kind of "selection pressure" between competing economic and social relations. Under animal-powered peasant agriculture, there wasn't much stuff to exchange, it was hard to exchange that stuff, and most of the stuff that was exchanged mostly could only be immediately consumed. The dominance of commodity relations (and thus capitalism) under these conditions was of course impossible. The predominant system of economic relations was feudalism (with many variants), which concentrated on military control of the land necessary for agricultural production, and all the political and social relations evolving to support and reinforce the feudal system of economic relations.
What changes everything is the invention of machine power. It suddenly becomes possible to transform surplus food into productive efficiency, by feeding surplus food to people who create steam engines and the ancillary machinery to use that power to create products.
At the beginning of the industrial revolution (and until the end of the 20th century, and even to some extent today in the beginning of 21st) machine technology was most efficient in specialized production; it was not efficient at making the ordinary (agricultural) workers able to produce all the various things they needed. It was vastly more efficient to build a shoe factory and produce tens of thousands of shoes than for tens of thousands of people to create machines to quickly produce their own shoes. Of course, now, these shoes must be exchanged. Thus commodity relations.
It furthermore becomes not only possible but economically feasible to raise the cost of labor power. There's only so much you can do under peasant agriculture to prevent periodic famine; despite his* best efforts the feudal lord just has to grit his teeth and bear the decimation of his work-force once or twice every generation. Feeding people more in good times doesn't translate well into surviving bad times. But improved agricultural productivity, food storage and transportation does indeed reduce famine. Improved medical technology and sanitation reduces death and disability from disease. Increasing the cost of labor power increases the labor available from the existing population of workers.
It required a fair amount of surplus to create a machine-powered factory, and even more surplus to feed the workers until the commodities one exchanged for the factory products arrived. This "high bar" gave social and economic privilege to those people able to somehow accumulate the necessary surplus to overcome that bar.
Relative to feudalism, commodity relations and the privilege of capital was pretty much a win for everyone (except for the feudal aristocracy). The capitalists got rich. Agricultural workers under feudalism lived at cost; living at a higher cost under capitalism was a direct improvement for ordinary workers. Sure, you had to work at a factory from sunup to sundown, but (to paraphrase P.J. Plauger) before capitalism you had to work on the farm from before sunup to after sundown, and in bad years you starved.
Politically and socially, the feudal aristocracy might have appropriated the role of ownership of capital, but in the main they did not. For centuries the means of production of peasant agriculture shaped and constrained all economic, social, political and legal relations. Social relations are in a sense the "memes", the principles, attitudes and habits of thought propagated from generation to generation more-or-less literally and seemingly for their own sake. All these habits of thought became ingrained into not only the workers but the members of the ruling class, the feudal aristocracy.
The habits of thought that make one an efficient feudal lord do not make one an efficient capitalist. Because habits are transmitted for their own sake, it's difficult for an individual to make radical changes to his or her own habits, especially when those habits have, for generations, "earned" him and his fore-bearers immense economic and social privilege. Hence most of the people who were efficient capitalists were not members of the feudal aristocracy and formed the then middle-class bourgeiosie*. Once the bourgeoisie amassed enough economic power, they violently replaced the feudal aristocracy as the ruling class in the bourgeois revolutions of the 18th and 19th centuries.
"Bourgeoisie" originally referred to townspeople in general, those who were neither agricultural peasants nor nobility. And even fifteen decades after Marx, "bourgeois" still carries connotations of the (now professional-managerial) middle-class and nouveau riche capitalist ruling class parvenus.
Strictly speaking (and notwithstanding Marx's backhanded praise) capitalism itself doesn't deserve any credit whatsoever. Capitalism — as much as improved productivity and workers' conditions relative to feudalism &mash; is a result of material economic forces. It's not like some guys got together in 1698 and said, "Hey, Thomas Savery just invented a steam engine, let's create a society based on commodity relations and the privilege of capital owners to take advantage of it." All the elements of capitalism emerged from material individuals doing material things for their own immediate material interests under the changed material environment afforded directly by machine power and indirectly by scientific thought.