@whatsofunnyaboutpeaceloveandunderstanding But you're kind of proving my point here by drawing out those examples - that there's some very vocal students featured in the media and being very visible on social media who create a sense that they speak for the whole student body.
But this Edinburgh Tab article doesn't give specific numbers of students that support the MAB, it only says that their Instagram account has been 'inundated' with responses to posts about the MAB.
Edinburgh has 45,000 students. Assuming that 450 students messaged The Tab to express their support for the MAB (which is a really high estimate), that's only 1% of students actively, vocally supporting the MAB. But some of these students are being plucked as mouthpieces for the student body which is creating a full sense of just how much students are invested in the action.
I'm not sure which petition you're talking about specifically but there's a currently active one from UCL students union which has 174 signatures. There are 43,800 at UCL. So 0.4% of students.
I think a lot of UCU people have a rose-tinted idea of students as radical, politically engaged and fighting for justice. There are a small number that are like this and they're the ones that appear in the media in support of UCU action. Most, though, like @ghislaine said, are pretty ambivalent about us and more focused on themselves. And rightly so.