If you want only people who are truly committed to make a longstanding contribution to a fight for justice, then maybe it is wack.
But if you want the "millions for mumia" then a lot of those are going to be less than fully committed.
I have the same struggle a lot of the time. I have been doing anti-dp/criminal defense work for the past couple of years. Everytime people just want to talk about Mumia, what he has suffered, how oppressive judges are etc. "No shit", I generally think, and then I tend to get mad that people only seem to get upset about this type of injustice when it applies to someone who is deemed "political" and doesn't seem to rally as much around someone who may not have Mumia's political leanings.
But then I remember that they are here because they care, and this is a great chance to talk to them about issues beyond the specific case, and get them involved in other struggles and issues.