I think one has to see populations as distributed along a normal distribution (a bell curve) or some other probability distribution rather than somehow coalescing to a single "representative individual".

Protesters represent one tail of the distribution on some measure (e.g. "belief in social justice"). The fact that protests get more intense and/or more frequent and/or more populous are indications of a shift in the distribution (picture a normal distribution being shifted along the x axis).

That's what I am pointing to. I don't think everyone has to be in lockstep to be able to talk about what a given group does or believes or what not.