This is not exactly true and many people have no idea. Early versions of the bitcoin client included an IRC client as well as some code relics of a would be poker game. Satoshi's early vision of bitcoin was probably that it could do multiple things from within the very client the payments are also launched. But nowhere do we get any idea that satoshi would have wanted the blockchain to be used as storage...
Satoshi specifically opposed the blockchain being used for data storage. But its apparent Bitcoin's users do not oppose using the blockchain for data storage, which is why they do it.