Given the fact that it is now accepted that they can rule on whether or not any law passed, and by extension regulations put in place in furtherance of such laws, is Constitutional, they surely can make law by leaving a law passed by Congress in place and altering into insanity how regulations implementing that law must be interpreted or eliminated.
If you dictate that regulations enforcing a law must be implemented in a way that is directly opposed to the clear intentions of Congress, that absolutely is "making law".