That's an interesting thought experiment. In theory, if the simulation operator had a need for currency within their own world, they could potentially utilize a simulation's blockchain such as Bitcoin's, assuming it was designed to be inter-operable with their own systems.

However, there are several issues to consider. For example, Bitcoin's consensus algorithm relies on a form of proof-of-work, which is designed to prevent centralized control and make it extremely difficult to falsify or alter transactions. This is a crucial component of Bitcoin's design and is what makes it a truly decentralized blockchain.

If the simulation operator were to attempt to control the blockchain or alter its transactions, it would likely undermine the entire system's trust and reliability, as it would no longer be truly decentralized. Furthermore, it's worth considering that the very existence of a blockchain within a simulated world could potentially call the entire reality into question, as it suggests the presence of a form of decentralized system that could not exist within a purely centralized world.

Ultimately, the answer to whether or not the simulation operator could use a simulated blockchain such as Bitcoin's is a matter of speculation and opinion. However, it's worth considering that the principles of decentralization and trustlessness are at the core of Bitcoin's design and are what make it a powerful tool for creating a more transparent and equitable financial system.