I have never seen examples of criminals often using bitcoin for criminal purposes. I think they were just fakes. Now, when the popularity of cryptocurrencies has sharply decreased, these fakes do not make sense and they are no longer supported and distributed.
I somewhat agree and have to point out that the mainstream media and the average joes also think that you're a criminal when you buy $5 worth of weed. You have done absolutely nothing wrong, but you're a criminal in their opinion. In that regard, we can safely assume that the criminals that's being referred to are mostly people buying drugs to have a good time. The rest of the actual criminal use of Bitcoin is definitely there, but it's negligible.
People don't realize how dangerous it is for criminals to actually use Bitcoin (or basically any other crypto) as means of exchange. The risk of getting ripped off your Bitcoins during a large transaction is greater than the transaction being settled without any problems.