If there is no incentives then why there is nodes on the network?

Here are your incentives:

Individuals - Fans that want to contribute to the network
                - Heavily financially invested individual that wants to contribute at securing the network
                - Others?

Businesses: - Perform analysis on the network
                 - Having a better control of the transactions they are performing
                 - Heavily financially invested businesses that wants to contribute at securing the network
                 - Others?

Miners: - Miners need to mine on a node at some extent


Since there is no financial gains to run a node, solutions must be cheap. Their is no doubt the free market will monetize on that.