For now and past, bitcoin is the point of reference for other crptyocurrencies. All other altcoins emerged by seeing existence of bitcoins. In future, no one knows whether bitcoin can be reference for other cryptocurrencies as new technology is developing day by day in this world of technology. Altcoins may be based on different improved technology. Whichever, cryptocurrnecy be reference point in future, bitcoin will be always remembered for being first cryptocurrency and bringing evolution in world of cryptocurrency.