Let them think what they want to; if they think Bitcoin is a scam, it doesn't make any difference for Bitcoin. Bitcoin has already proven what's in it; those who want to call it a it a Bitcoin scam don't really know how a decentralised currency works. Bitcoin wasn't created to make us rich; it was a p2p decentralised cryptocurrency to make a solution for a borderless payment system without a third party. How would Bitcoin be scammed when it wasn't controlled by anyone? Due to a lack of proper knowledge, a few people think Bitcoin is a is a scam. We aren't concerned about it.
If Bitcoin were to be a scam how can it be so that Bitcoin has developed this much from 2009 till date. I think those who thinks Bitcoin is a scam has little or no idea about Bitcoin.
If Bitcoin is a scam how was the scam meant to go? The adopters of Bitcoin is on the rise even countries like El Salvador are benefiting greatly from Bitcoin.