Decentralized means there is no single point of authority.

So a company owned by two or more people is decentralized?

By your definition Bitcoin isn't decentralized

If one pool has > 51%, would people still trust Bitcoin? With Steem being in the hands of 21 witnesses, no one complains, weird.

everyone can be a witness

No one is allowed to complain about politics because anyone can be the next president.

And people don't become whales over night

You are going to be a whale within minutens when buying a huge load of Steem.

How many new whales have been created in the months before?

Why are you asking me? You claimed to personally know people buying so many Steem suddenly.