Was Marbury v. Madison a usurpation of power by the Supreme Court or would the absence of judicial review "subvert the very foundation of all written constitutions?"
Given these two choices, the latter choice is the more accurate one.
First of all, it is very hard to say that the Supreme Court usurped power. In order for power to be usurped, it must belong to someone in the first place. That was not the case with the power of judicial review. The Constitution was silent on the issue of what governmental body (if any) should have this power. Therefore, the Supreme Court could hardly have usurped the power.
Second, it was important for the Supreme Court to take that power. If it had not, there would really have been very little point in having a written constitution. If the legislature and/or the executive had the power to decide what was and was not constitutional, there would have been nothing to stop them from wielding as much power as they chose. By definition, Congress is not going to rule that a law that it has just passed is unconstitutional. It would not have passed the law if it felt the law was unconstitutional. The Congress could interpret the Constitution however it pleased and there would be nothing to stop it.
Therefore, it was important for the Supreme Court to have the power of judicial review. By taking this power, it helped to ensure that our written constitution would remain relevant.