Looking at hash rate shares historically, it is incomprehensible that market share would remain so stable through several generations of mining tech. So the existing system is precisely a cooperative benevolent monopoly, albeit an informal one. My guess as to why the miners don't just turn off their equipment and threaten to overturn any non-monopoly block mining is that they just don't know how much of the speculative bubble is based on their behavior, and acting that way might pop it.
You dumb, "benevolent monopoly", not even close, miners are selfish and greedy, far from benevolent. If it was more profitable to attack the network with their hash power they would, but they would be essentially scrapping the $millions they put into the hardware.
