Nobody has to buy into the USD, it's already there, established. Bitcoin has to be better than the established norm in order to succeed. It is in some ways, don't get me wrong, that's true. But it still isn't perfect, and I personally think a better implementation will succeed in the future.

Namely, one where the majority of "little people" can mine the coin. Or one with a fair and equal distribution to at least hundreds of millions of people (preferably billions) before the coin is launched.

Those were some of the founders original ideas, that anybody with a CPU could mine the coin. And technology slowly took over...

I think the parent commenter's point was that Bitcoin was billed as a solution to the problem of the few holding most of the money, yet has appeared to fail in that regard, and continues to fail as mining is increasingly inaccessible to all but those who are sufficiently wealthy to afford warehouses full of state-of-the-art ASICs.

This isn't to say that Bitcoin hasn't succeeded in a lot of fronts. Just that one of the key fronts - one of equal ownership of the money supply - hasn't been quite as successful as others.