...why doesn't it persuade anyone who isn't already convinced?

That's a good question. In fact, considering the history of this century, it's a damn good question. I've thought long and hard on this over the years, and wish I had an answer. I have some vague theories, but I won't go into them here.

We live in a complex and interrelated economic jungle populated by organizations deliberately designed for nothing but endless growth and self-perpetuation. Some form of regulation and centralized planning is not only inevitable, it is essential, because in an economy dominated by these organizations and their agents, they will always find a way to pervert the very mechanisms that you trust to self-regulate the system. That's their job, and they are selected for excellence at it. They will get their way, or they will wreck the economy trying to run it strictly for their benefit, as recent events so clearly demonstrate.

Just to make sure: You're talking about private business here, not government bureaucracies, right?

You might want to study the "recent events" and the players more closely.