Scam shouldn't be used as a label for Bitcoin at large, but the hype machine and pump-and-dump schemes around Bitcoin are most certainly teetering on the lines of being a scam.
Bill Harris, former CEO of Intuit and founding CEO of PayPal and Personal Capital, writes:
Promoters claim cryptocurrency is valuable as (1) a means of payment, (2) a store of value and/or (3) a thing in itself. None of these claims are true.
- Means of Payment. Bitcoins are accepted almost nowhere, and some cryptocurrencies nowhere at all. Even where accepted, a currency whose value can swing 10 percent or more in a single day is useless as a means of payment.
- Store of Value. Extreme price volatility also makes bitcoin undesirable as a store of value. And the storehouses — the cryptocurrency trading exchanges — are far less reliable and trustworthy than ordinary banks and brokers.
- Thing in Itself. A bitcoin has no intrinsic value. It only has value if people think other people will buy it for a higher price — the Greater Fool theory.