The legislature, not the courts, make the laws. The courts themselves are subject to the restraint of the legislative branch - and if you don't believe me, check out Article III of the Constitution. The legislature, which should have the final say in the matter, has been blocked by a rogue judge.
Which brings me back to my original question: would someone (Terri's parents, or others closely involved) be justified in undertaking civil disobedience and keeping Terri alive - or even attempting to rehabilitate her - against the will of the judge?