This is unenforceable. California has no Texas Rangers that can hunt you down in other states. California has no standing in another state's courts for collecting this tax. And that's a good thing too. Consider child-support payments --- they require states to cooperate. But you may never be able to enter California again.
Unfortunately it's not that simple. California (and every other state's) law already says that their taxman need not go through the courts to seize assets but can do so directly. If their tax collector contacts you and you ignore them because you don't live there, they'll just seize the money from your bank account (no matter where you are) and you'll be stuck litigating in California tax courts to try and get it back.
This already happens routinely-- look up the various cases of people who left California, and then the state came after them under the theory that they never really left. Here's a case[1] where they spent 25 years harassing a guy who moved out.
Even if you leave the country, you can be extradited since failure to pay tax is a felony. Unless you went to Russia, which doesn't extradite.
