TH, I guess the point of contention is supporting someone who is known to do nefarious things. If you knew, for example, that you enjoyment in the form of internet clicks, page views, netflix watches - which all translate into monetary compensation for the owner - does that bother you?
That separation is enough to justify one way or the other, but would it bother you if there was a direct connection - you walking up to said person and giving them money explicitly to fund their nefarious behaviors? I think a lot of people feel that that's exactly whats happening when you show support for past works.