I think many people thought it wouldn't happen, that the US would stop it somehow.
Now it has happened already, so quickly, the market is now starting to react.

But most people think "small, poor country, so what" and don't understand the massive tax, accounting and geopolitical implications.

It also creates a concentrated geographic market of 6.5 million BTC users, which is a very attractive business opportunity for any crypto related business.

It will take some time for the full implications to filter through to the market.