Also the Sierra Club, an organization that exists "To explore, enjoy, and protect the wild places of the earth" shouldn't be lobbying in labor rights issues. It muddies their actual goals.
All of their members can, and should, organize for those causes, but the larger organization and local chapters themselves shouldn't.
Focus on the goal not the noise. Build bridges where and when you can. Someone doesn't have to be "all-in" to be an ally.
/rant
I just so want causes like theirs to succeed. But to succeed you need to play to win.