Well yeah it would. The whole point of crypto is that it is SUPPOSED to be a decentralized currency, if it can be controlled which country can use it then it is no different then a stock exchange, and the value will plummet.
Is locking russian citizen out of their holdings the "right thing"? Because that is one hell of a slippery slope. Canada just had some experience with this as well.
Sure, punish putin, punish the oligarchs that own most of the country, but the regular citizens? That's going too far.
I mean imagine if the whole world decided to freeze your bank account in new york because the US government bombed another 3 iraqi children.
At the least everyone in charge circa 2008 should have been drawn and quartered. The problem with all the financial systems is the people in charge taking advantage of other people, not just that it occured in a building called "bank"