frumsinglegirl-
I won’t debate whether or not they are disgusting lowlifes as you say. My question is, would you have any objection to using tissues made by the same person? How about to using a mathematic principle formulated by such a person? Maybe this is a surprise to you, but the halacha treats music the same way! In halacha (see the sources I cited above) there is no such thing as inherently bad or non Jewish music, inasmuch as there is no such thing as non Jewish tissues or a non Jewish math problem.
Granted, there are those who claim that there is a ‘hashkafic’ problem (which I do not agree to). But with no halachic source to say it is assur, and in fact explicit sources which are matir, how can you pass judgment on people who simply rely on Shas and Poskim?