So I read this Wikipedia article and it says this: "Buterin argued that Bitcoin and blockchain technology could benefit from other applications besides money and needed a scripting language for application development that could lead to attaching real-world assets, such as stocks and property, to the blockchain ... he proposed the development of a new platform with a more general scripting language that would eventually become Ethereum."
He was making such statement after seeing how bitcoin and its blockchain. That's the real purpose of why he was creating the smartcontract.
FYI if ethereum smartcontract started from the bitcoin source code and what he means about adding more script to create various function that can be used to create tokenization backed by the real asset.
The statement that you have mentioned above is related to why smartcontract being introduced by him.
You must also read what code that being used to build the smartcontract and it was using the bitcoin source code + combined with the new script like solidity = smartcontract of ethereum and EVM that can be used for a tokenization for the real asset like property, stock and various things even build various defi platform that offered the same thing like traditional banking system.