Fighting it without any effects is much worse than not doing anything. I'm sure some countries have thought of it, but analysis has proven it to be not worth it.
Bitcoin is not threatening to destabilize the government, so there's no need to fight it and doing so might prove to be futile. How would you stop an online project, that isn't supported by your local servers? You can't go to neighboring countries and start arresting people, and arresting node runners and miners in your country wouldn't stop anything.