Something should be centralized.
Not everyone is educated.
Look at those scammers and thieves who are on always on a prowl for unsecured sites, they do it because there is no central entity that will fuck him up if he did those things.
So, we sometimes need it.
Like it or not we are heading towards a totally decentralized technological future, or at least the option of being at a totally decentralized internet.
Yes of course, the idea of decentralize everything is good but the process might be very very difficult because some people dont like to "decentralize" all the life aspect (yes I know it is hard to understand, but this is true). The freedom and the decentralization are really correlated.
some people don't like decentralization, because it take away the security, you need always to trust a third party with decentralized system, that's the only problem i can see, otherwise decentralization is the future