The downside of centralization can't be seen by the winning centralized player.

"Why does everyone dislike me? I'm doing nice things for them! I think this setup works pretty well for everyone! Everyone's lucky to have such a good guy like me holding all the power. Imagine how bad it would be if my competitor held it and how much everyone would dislike it, since my competitor is obviously not as kind-hearted and good-willed as me!"

It is hard to see the downsides of your own power, but easy to see the downsides of others' power.