I have zero doubts that Bitcoin can survive nearly anything, the point is that just surviving is not enough, to be called antifragile a system should retain all it's qualities after the attack, basically emerge unscratched and even stronger than before. It can't be always the case with Bitcoin, even something as simple as a big price drop has huge consequences - it undermines its usability as a store of value or a currency. You're saying that only short-term traders worry about that, but short term traders actually like that, because they can make money on sudden price movements.
Huge price drops have been happening for 11 years so far and bitcoin is still alive, got even stronger than before. Also, in case of something that has a potential to become store of value, short-term might mean even couple of years, it always depends on the particular purpose.
Regular people aren't comfortable with storing their money in something that can go 50% down in a day. Just imagine receiving salary in Bitcoin and finding one day that you can't pay your monthly bills because the price has crashed.
Just give these people a right to choose what currency they want as their salary. I believe some of them would choose either a combination of bitcoin plus dollar or pure bitcoin. I myself would prefer the latter, because currency in my country sometimes more volatile than bitcoin.
Or take something like a global ban - sure it's not 100% enforceable, but it doesn't need to be, it can scare off the majority of current and potential users. It won't kill Bitcoin, but it will make it small. Anything that reduces Bitcoin's number of users makes Bitcoin less valuable, the network is less secure when there's less hashpower and less nodes, it's easier to attack it or monitor it.
After bitcoin survives the global ban, it will be the most robust technology ever known, because all people around the world will be aware of such grandioze robustness, bitcoin will be adopted faster than any other technology ever created.
