There are significant reasons why having a deflationary, digital currency (or commodity) would be quite useful, at least for certain people and use cases.
If there were no use case for Bitcoin, calling it a scam without presenting evidence would be much more reasonable. Given that there are use cases, calling Bitcoin a scam without presenting evidence is completely arbitrary.
To make an analogy - if I ask you to invest in my company that makes a brand new food item with no nutritional value or flavor, it's probably a scam. However, if I ask you to invest in my company that makes a tasty and nutritional food item, regardless of whether you think my food will do well in the market in the long run, it requires evidence to claim that it is a scam.
I didn't say Bitcoin itself is a scam, only that the market is so tiny that a single player could easily manipulate it. And if someone can, someone will. And while I see Bitcoin's legitimate use cases, few (very few) people are using it for actual trade. The market seems purely speculative, with no underlying Bitcoin economy to stabilize it (save possibly the money-laundering business).
I agree that the market is largely speculative. But I think the speculation is mainly very long-term speculation - so people predominantly want to get more bitcoins, or they want to hold them. This will tend to drive the price up.
There are significant reasons why having a deflationary, digital currency (or commodity) would be quite useful, at least for certain people and use cases.
If there were no use case for Bitcoin, calling it a scam without presenting evidence would be much more reasonable. Given that there are use cases, calling Bitcoin a scam without presenting evidence is completely arbitrary.
To make an analogy - if I ask you to invest in my company that makes a brand new food item with no nutritional value or flavor, it's probably a scam. However, if I ask you to invest in my company that makes a tasty and nutritional food item, regardless of whether you think my food will do well in the market in the long run, it requires evidence to claim that it is a scam.