Thoughts about decentralization

Many people's excitement about bitcoin is that it uses mathematics to create a system
that is inherently decentralized, where no minority can gain a lot of power.
This is the idea behind the motto `In Cryptography We Trust'.

I am skeptical about this as in any system you put human beings in,
their natural tendency would be to accumulate power, and they will find ways to do so the system had not anticipated, and ultimately the most greedy and\or talented of them will gain as much power in this system as a dictator has over his country.
Indeed this is what is happening in bitcoin with the so-called mining pools and mining farms.

This is why I first thought - technology can create a different world, and perhaps the historical process of change is an interesting experiment the universe is conducting, but it cannot create a better world.

..but maybe the following is true: The more  a system has a decentralized structure,
the less violent will the expression of power and control be.
 For example, in democracies the people controling the banks and the media might have as much power as a dictator for practical purposes, but the expression of that power tends to involve less killing and torturing, at least of their own citizens.

Why would it make it sense for this to be true?
I think because the minute those with power would use it too violently, it would break
the illusion of decentralization - the facade that the power is with the common people.
And if the system is working well for them, breaking this system is not in their interest.