Like many things, the discussion is entirely subjective.

If you compare EOS to a large scale meshnet, it's centralized. If you compare it to a system which relies on a single organization, it's decentralized.

The better question is whether or not the current level of (de)centralization is sufficient to accomplish the goals of a particular project. Not everything needs to be distributed across a ridiculous number of nodes. I think that the biggest argument from the "it's centralized" camp comes from the fact that the vast majority seem to think of cryptocurrency as just that, a replacement for centralized currency systems. What is best for something designed to be a currency is not going to be what is best for a utility token focusing on a different use case.