In my experience Core Dao is a very fast(almost instant) cryptocurrency, it also combines the advantages of bitcoin and ethereum. Created by an anonymous group and has its own loyal community. But surprisingly its existence seems to be ignored by centralized brokers. Is it because its existence threatens CEX coins, or because its creator is an anonymous group?

Of the many coins, only a few were created by anonymous people, the most famous is bitcoin. While the majority of other coins are created by individuals/commercial groups.

Shouldn't cryptocurrencies be anonymous and decentralized? If not then what's the difference with regular e-money?

It's really unfortunate how people so easily deviate from the purpose of the existence of cryptocurrencies themselves.