You are presenting the Marxist definition of Capitalism, not the Capitalist definition. You've disregarded the key point in my definitional first paragraph, which is that the most essential feature of capitalism that the owner or the owning company has the right to keep and use their profits however they see fit. Don't disregard this, it's the main issue.
You are also making the move of conflating Capitalism with the broken and corrupt system we have today, where the essence of Capitalism is almost entirely crushed under the burden of regulations that are often written to repay large corporate donors to parties and politicians, regulations that tilt the natural playing field and make a farce of actual competition. From this corrupt soil grow the things you complain about re Microsoft, etc. These distortions are not part of Capitalism, they are part of what is breaking Capitalism.
Marx apportioned the moral ownership of value to the muscle power of workers. It's as though the designs and production processes they work on just spring up out of the soil of the proletariat like free fruits from the tree of 'how everything works'.
How would Marx deal with the case of today's single creative individual who gets an idea for a product, designs perhaps an electronic circuit that makes the product work, designs the enclosure, defines the user interface, writes the advertisements, launches the product, assembles and tests each instance of the product, and does whatever else remains of the entire process as a single capable individual?
How will Marxist theorists deal with a world where the divisions between labor, management and ownership no longer apply?
Briefly regarding shares versus bank loans: The buyer of shares from an offering is investing in the venture. Unlike with a bank loan, the venture does not have to begin to repay the loan. Shares are repaid according to the value of the company. Shareholders may wait for years before cashing out. And how do they cash out? This is what the trading of shares creates: a liquid market for the shares that tracks the company's valuation and provides buyers for the sellers. Selling shares is vastly different from taking out loans, and for a growth business, selling shares is vastly more preferable.
As to the "right" that shareholders have to the the future value of their shares: that value may be higher or lower. Whichever is the case, shareholders have earned that future value by exercising their reason and acumen in selecting those shares above other shares. They have directed the flow of capital. And yes, they had to pay out the money to acquire the shares too. It's bizarre that anyone should claim they don't deserve their "share of the work of others." It is often because of shareholders that those 'others' have any work to do. Shares usually provide no ongoing income and are at risk of losing value right up until the moment they are sold. All the while, the 'others' get a dependable paycheck every pay period - a comfortable status that shareholders often make possible.
Marx is the past. People following Marxism today are thus necessarily living in the past. Forget Marx's forecast of revolution. Stop trying to "bring about true history" by promulgating Marxist ideas; stop trying to force a revolution that failed to occur naturally. It did not happen because the core ideas of Marx are just wrong. These ideas are not "noble," as so many conservatives like to say when they denounce Marxism. The truth is, his ideas are not noble. They are wrong. Being wrong, they will always produce terribly negative results -- as we have been shown in reality, over and over again.
And why should it be so unthinkable that this one man should be entirely wrong about so many things? This is not such an uncommon occurrence. Reality often makes fools of us. It is essential to learn from the lessons reality provides and to let go of ideas that have failed and failed again.
Real Capitalism demonstrably succeeds wherever and however imperfectly it is tried. A tiny dose of Capitalism's retained right to profit recently brought almost a billion Chinese out of abject poverty. No one seems to acknowledge this. There are no parades, no glowing documentaries. Can you imagine the gushing coverage there would have been, has some kind of socialism or communism been responsible for this recent miracle of productivity and wealth creation in China? The Chinese communists applied a small dosage of essential Capitalism and grew an economy that rivals that of the US - and now they are destroying it because they fear the political freedom that goes with it.
Really, it's time for thinking people to climb out of the intellectual prison of Marxism. You can help save Capitalism from those working to destroy it. Most Marxists are actually motivated by what they consider to be a noble goal. Well, in actual Capitalism you have such a goal. Help save an idea and a system that has been repeatedly demonstrated to work benevolently in reality. Now this is something worth working toward!
