> why couldn't Russia extradite someone for ignoring Russian censorship takedowns
They can, in countries that have entered into extradition treaties with Russia. That's how treaties work.
In this case, the courts seem to think Dotcom was breaking both US and New Zealand law, and in the treaty New Zealand has with the US, they've agreed that someone could be extradited in those cases.
If Dotcom wasn't found to be breaking New Zealand law but only US law, it seems he wouldn't have been extradited.
They can, in countries that have entered into extradition treaties with Russia. That's how treaties work.
In this case, the courts seem to think Dotcom was breaking both US and New Zealand law, and in the treaty New Zealand has with the US, they've agreed that someone could be extradited in those cases.
If Dotcom wasn't found to be breaking New Zealand law but only US law, it seems he wouldn't have been extradited.