Consensus nodes aren't competing for consensus, they're cooperating. This leads to one significant advantage:
This advantage is crucial. Financial and economic usecases of #blockchain need fast finality for a smooth experience.
Since at first only 7 nodes are involved in consensus you have to be careful who to trust with a consensus node.
To manipulate blockchain data, the bad players would have to own >66% of consensus nodes (5 nodes right now, which is highly unlikely)
Since 65M NEO are in circulation those holders will gain a significant influence on NEO chain.
NEO will have more than 7 consensus nodes in the future so more and more entities will be able to get hands on NEO consensus
But why does it take so long? Because dBFT is vulnerable at first but becomes very resistant to attacks with every new node.