i'm in favour of cultural appropriation, actually - i strongly support the idea of appropriating religious imagery into secular contexts, in order to strip of it of the religious meaning and reframe it without it. that is a powerful tool that atheists should utilize to purposeful effect.
if that upsets you, we're operating at clear cross purposes.
it has to be interesting to listen to, though. if it's just appropriated for the sake of appropriating it, it will probably be as boring as it would be in the initial context.
but, if you can take religious or ethnic music and update it in a way that separates it from the religious or ethnic context and presents it in an interesting, modern, technological and/or secular context instead then i actually think you're doing something positive, and progressive and forward-thinking and will stand in solidarity with you as you do it.
just try to avoid mocking the legacy cultural or religious ideas too deeply, as you upgrade them for the future. there are some things that deserve a good verbal drubbing, granted. but, there's a line you shouldn't cross that is both difficult to abstractly define and easy to identify when you see it.
i've been open and consistent on this point for years - this not only doesn't bother or offend me, i'm in support of it as a way to drag certain conservative worldviews into the present, and also as a way to break down tribalism and insularism.
the criticisms of appropriation have always been very conservative in scope, and have always belonged on the right of the spectrum.