Earlier quoted context omitted.
You can make money from stealing anything of value. What is strange about it?
Normally if you stole euros you wouldn't need to first sell them for dollars to get value out of them. Cryptocurrencies are not currencies, not any more than rare postage stamps are.
I can't pay with dollars in most of the shops in Poland. According to your logic, a dollar isn't a currency, not any more than rare postage stamps are.
Or, in other words - why and how do currency exchanges exist, then? They literally sell and buy different kinds of money.