Some arguments used against cryptocurrency :

1. Cryptocurrency is a Ponzi scheme

The whole economic system beginning from demand and supply is a Ponzi scheme because in demand and supply, someone profits from the loss of someone else.

2. Cryptocurrency has no intrinsic value

A government stamp on paper does NOT give it intrinsic value. With your fiat so-called intrinsic value, why does the value of all fiat keep on dropping in value?

3. Cryptocurrency can be used to evade tax

The ONLY legal tax is income tax and nothing else. And it is not wrong at all to not pay all of those extra so-called taxes to any government whether good or bad.

4. Cryptocurrency can be used for terrorist activities

The internet itself is used for terrorist activities. Gold and fiat money also is used to fund terrorist activities and are done in private. So how will you regulate those dear regulators?

5. Cryptocurrency can be used for money laundering

I can money launder with gold also by simply burying the gold and hiding it from the eyes of tax collectors. I can similarly make private and corrupt transactions with fiat money also in secret.

6. Cryptocurrency is volatile

Stocks are also volatile. Check out how volatile the Amazon stock has been.