The proof that that's not true is that whose second-generation sharks DO appear. Not all small companies get squashed, and some of them grow large enough to grow into sharks themselves, thus breaking the monopoly.
For most small businesses it doesn't really matter whether IBM, Google or Microsoft are dominating the market and when this changes. It's still a huge company lording over the smaller ones. I think we would be much better off if growth beyond a certain size would be disadvantageous for a company and it would become less efficient. But with today's progress in automation and communication you can run a large company world wide in a very efficient manner so it's even harder for small competitors to keep up.
