There has been a surge in chains being halted for whatever reason. DDOS, network instability, bug are common explanations given for why the chain was halted.
If you dig into these incidences, it seems all of them were halted after discussions on discord groups by the validators of the chain and all of them arrived at the conclusion that given the situation its better to halt the chain till the issues are ironed out.
How can these kind of validators be expected to keep a chain up if governments of the day decide it is required to shut the chain down? They wont, they will fold immediately. The effort required by a government agency to shut these chains down will be minimal.