No, the justiciability of human rights is not a concept that international courts can enforce, because each nation would have a different idea about what justice for human rights would mean. It would become political, and it would become a way for less-capitalist nations to control more capitalist nations and their wealth.
No it is not one that the international courts can enforce. It is up to each individual country to determine what is Justice for them. American's view Saudi Arabia as a harsh way to punish their criminals. Yet they don't have the crime rates that we have in America they know their laws.
The idea that International courts can enforce human rights around the world, though admirable, and something to strive for, is fraught with difficulty. As long as nationalism exists, international courts will always be limited by degrees of cooperation from national governments. Since a government that is most likely to cooperate with international justice is one that is less likely to commit human rights violations, the court can only act as an ideal to model the future upon.
Justiciability is somewhat of a litmus test for the United States Supreme Court to decide rather or not a case can be decided by the judges. I have my doubts justiciability of human rights is a concept that international courts can enforce. Courts generally make rulings on laws, they don't enforce them beyond sentences for those who broke the law.