The majority of the public doesn't even really want to understand Bitcoin properly.
I don't think it's a matter of them not wanting to understand Bitcoin, but more so that the way they use Bitcoin comes down to leaving it on exchanges and from there send out and receive Bitcoin.
Based on that basic form of (stupid) use, they don't need to dig further. If their needs are met, which seems to be the case, they know everything they need to know. Using an exchange is the simplest thing there is.
I don't think there's a case of criminals loving Bitcoin at all, I think people just think, wrongly, that the extra few steps necessary for enforcement to track them down, is enough of a deterrent to keep them safe. That, or just plain ignorance and carelessness you would expect from kiddy hackerbois.
I think people are waking up slowly but surely-- I have seen enough to know that the criminal use narrative is shifting from Bitcoin to XMR and other privacy coins. People even ridicule Bitcoin for not being private.