> If it turns out that 90% of (you name the group) are not discriminated against, but 10% are, does that mean that we should ignore that discrimination?

At the very least, it might mean you don’t bring in an activist that antagonizes members of the majority group, as was allegedly the case here.

Activism undertaken on behalf of a minority group affects the relationship between that minority group and society as a whole. All members of the group have a stake in the overall relationship between the group and other groups.