The number of blockchains are growing each and every day. Just as most things in life (i.e. insurance, education, companies, etc.) there are private services with a business model for their offerings, and public services that are open to anyone who wishes to join.
Likewise, there are private blockchains and public blockchains.
The problem however is the growing disconnect between the two, further inhibiting a seamless user experience and a single blockchain.
Just as there is one internet, there will soon be one blockchain, potentially with many sidechains, comprising of both public and private chains.