Let's say I created a system. Then I say to people: "invest your value in my system". And people do that.
Let us stop here for a moment. In your fictional scenario, why do you think people would "invest their value in your system"? I think that is an important part.
Because I wrote a paper in which I claimed that my system has revolutionary money.
However, once people invested their value in my system I said to them: you are unable to return even a dime worth of value from my system, and if you want to return your investment, you have to wait for new investors to bring value into my system. Would you call me a scammer, and would you say that my system is worthless?
Yes. By luring investors with false promises about your "system," and later changing your terms, you would be considered to have deceived your investors, thus labeling you as a scammer.
However, I am not sure how this relates to Bitcoin in any way.
It relates to Bitcoin because people invested in the bitcoin system based on Satoshi's promises of money in the Whitepaper. Money is some kind of value that benefits people. However, no such value exists in the bitcoin system, which is why the investors are unable return their investment from within the system. Instead, they must wait for the investments of new investors for these returns. Hence, a textbook definition of an investment scam. In a legit systems, investors are able to return their investments from the value that is present in the system or that is created in the system - as I explained above in the two examples (Tesla, fiat currency system). If there were value inside the bitcoin system, then the current holders would use their evidences (certificates) of investment (bitcoins) for the access to that value. The same as certificates of investment in the Tesla system (stocks) or fiat currency system (deposits and banknotes) grant access to the value present or created in these systems. But given that no such access exists, these certificates, that is bitcoins, are just fake data. Something equivalent to counterfeit money.