"There are people driving cars to commit crimes, like bank robbery!"
Oh no! Now all cars and their drivers are criminals, I suppose? Grandma driving to the grocery store surely is up to no good?
I think the claim being attempted is that crypto is mostly used for crime. Yet is that true? How many transactions happened yesterday? And how many were nefarious?
The biggest bucket is going to be purely financial trades. This is true whether you're trading wheat or copper or oil or whatever. Anybody who thinks they can make a dime but doesn't actually want any of the underlying is here.
Then of the rest, you split by social value. For the traditional markets, most of these trades will be socially positive. Wheat buyers and wheat sellers are mostly making things that people actually want and benefit from. Anything like that is in the "positive social value" bucket.
The third bucket is socially negative. In the traditional commodities, this includes the people who were trading nickel but just swapped in rocks, and other kinds of fraud. Or if you were a terrorist who was buying oil to dump it on the Great Barrier Reef, that'd be there too.
Most crypto trading is in the first bucket, because that's true of almost any financial market. People who need the underlying don't trade much compared with people who are seeking financial advantage. But of the rest, unlike traditional markets, most of the non-financial trades are socially negative. Cryptocurrencies main non-trading uses are things like ransomware, scams, pump-and-dumps, rug pulls, and money laundering, plus other efforts to evade the controls of the traditional financial system.
So the right societal question is: Ignoring the financial traders, what's the ratio between the socially positive and socially negative uses of the underlying?
If you look at my last two sentences, that is precisely what I said, so saying it's "not the right question", then asking the same question isn't very fair.
Your analogy, driving cars, certainly primes people in that direction, as the great bulk of current car trips aren't caused by traders looking to make a buck off the underlying motion of the people who actually need to get somewhere.
I think you're also grossly misunderstanding the most relevant claim, which is not that most crypto trades are directly criminal. I think most informed people agree that these days the bulk of them are speculative. (But speculators can speculate in anything, so crypto doesn't add anything to the world there.) The common claim is instead that the places where crypto has a direct advantage for actual use are mostly criminal.
And I think that's pretty obviously the case. When you compare the original Bitcoin paper with the current state of things like online bill pay, debit cards, Zelle, Square, Cash App, Venmo, M-Pesa, and the like, it's clear that Bitcoin has failed in it stated goals. It's just not very good at solving the problems normal people have transmitting money. Who needs to move money around but can't use any of the effective legit options? It's mostly criminals.
It's not enough to look at whether the day-to-day work "feels like a normal job", or "looks like a normal job" from the outside. You can have a highly respectable job while interacting with people who all look like stereotypical movie mobsters (e.g. prison social worker). You can also sit in a respectable office all day wearing a nice suit while committing genocide.
-- Shards of Honor by Lois McMaster Bujold
I need your book recommendations, or reading list :)
My main caution is that I wouldn't start with Pratchett's earliest works--there are already bunch of suggested reading-order guides out there. I spent a decade thinking Pratchett was overrated because I started with the wrong book. (IIRC The Colour of Magic seemed just too much of a parade of absurd situations for their own sake.) I like the City Watch books (starting in Guards! Guards!) and Small Gods is a decent stand-alone.
For Bujold, the Vorkosigan series is the flagship, where I'd put the Curse of Chalion (fantasy) as a second.
I mean... whether it's true or not, it sure _looks true from the outside_.
What it looks like from the outside has little bearing on the underlying reality, but it's extremely relevant to questions like "will I be viewed with suspicion for having worked with this" or "is my company likely to end up subject to restrictive regulation".
Assuming (I genuinely do not know) that the crypto industry has got legitimate uses which are not dwarfed by illegitimate ones, it has got a _massive_ image problem - because "everyone knows" it's for crime.