Odd that you would bring up a tool banned in a wave of media-provoked hysteria, one so useful to the disabled that the ban has been overturned, which was never in fact intended as a weapon, isn't a very good one, and just looks cool.
Probably because banning knives is ludicrous behavior, so there aren't better examples.
You're right - the switchblade is an odd example. I've now learned a good bit about it from that link!
But the core point is that societies will ban things that generate more harm than benefit, be it real or perceived. This is the crux of the gun debate in America right now.
It also depends on context. You can't bring a kitchen knife on an airplane. You will get funny looks from most if you walk around outside with one, even if that isn't specifically banned, but laws evolve out of social convention, so if enough people did it, you could plausibly see it legislated. I'd bet that if you committed some other offense like public intoxication or indecent exposure, and then resisted arrest, you'd have a couple knock on charges regarding said knife.
So here's the context for TD AFAICT: crypto is a competitor to fiat currency and all the hegemony that comes with it. It is a power play, and power doesn't come for free, and often is ultimately paid for with blood. Governments aren't just going to let a new wild west open up on that without any say-so. I think crypto enthusiasts either don't understand the implications of the tech or reject them on philosophical grounds, which I sympathize with but understand that doesn't change the reality as far as every stakeholder is involved.
True, walk around with a Ginsu knife outside and you better have a chef's hat on...
I'm not sure I 100% agree with the statement "crypto is a competitor". Sometimes it's a currency, sometimes it's a commodity but at the end of the day, it's a store of value that humans own.
US dollars deposited in a bank and crypto in a wallet are owned by the same people, so it cannot be a competitor. It's just another asset class. The fact that Coinbase is a publicly traded company shows that the US government 100% accepts crypto as what I've described.
What they do care about are items and processes who's main purpose is for illegal activities. Guns are a perfect example. You want to buy and register a gun from a licensed dealer, no problem. You want to buy one from a guy in a van and scratch off the serial number, that's a problem. In the eyes of the government, Tornado Cash is too much like the guy in the van.
Probably because banning knives is ludicrous behavior, so there aren't better examples.
So you can see for yourself: https://en.wikipedia.org/wiki/Switchblade