Ethereum was also a scam, which would have given you 10,000,000% profit?
In fact a lot of scams can be hugely profitable -- even ponzi schemes if you're not at the lower layers.
Is it a scam when you invest in promising technology that, yes, could not work out?
Oh, most of those people do know -- or should know better.
>Is it a scam when you invest in promising technology that, yes, could not work out?
In "technology that might not work out" alone, no.
In "BS application of technology just because it's in fashion, with no business content" yes.
Furthermore, Smart contracts are a business content.