There are, IMO, very grave and very serious double standards at play here because I don't think we're going to see any of those.
That is only pragmatic, right? Speaking up might actually change things by putting these relations at stake. For Iran, there might not be much left to do from a western perspective except military involvement. Starting another war is not something a Greta led flotilla might want to do.
I think the real reason has to do with 1) there was an existing, organized pro-Palestinian movement that had experience protesting; 2) many organizations on the left saw the Israel-Gaza conflict as fitting very nicely into their larger anti-imperialist ideology in a way that other conflicts don't; 3) everyone more-or-less knows where Israel is on the map and has some familiarity with it; 4) there were a lot of really shocking images and video from Gaza