If someone is using Tor, it doesn't mean that they are some l33t cypherpunks, it's likely just people who want to buy drugs online, and use that browser because that's the only way to access .onion sites.
True. Back when reddit still hosted various DNM subreddits, you could read people confessing what, when, and how they buy with bitcoins bought on Coinbase and sent straight to a DNM. Or thinking just adding a single hop with no mixer/coinjoin/whatever is enough.
Almost every time a DNM (or sometimes a DNM vendor) is taken down by some government's authorities, they can get many customers' personal information. Given the risks they're subjecting themselves to, a hell of a lot of people are as dumb as a sack of bricks.