It's simply disappointing. Rich gets richer. Poor get poorer. The power is distributed among riches, and you still call it "decentralized". It is centralized in riches.

Amazon was praised sometimes because of its long tail strategy that allows books with high quality but not common, accessible to people.
Such books don't bring many sales each, but on the whole, bring a lot.
And now Amazon is so big.
It is not only a matter of sales but also the idealism of promoting "good books" and the variety of books.

I think the change will de-promote the variety of posts, and only the posts talking about bitcoins or whatever popular topics will remain.