Hm, this was indeed a very refreshing lecture. Never suspected before that this form of separatism existed... Though I have my peculiar views on the issue of adult supremacism, I acknowledge both the entirely justified claim for more rights and self-determination of young people, as well as the intellectual accomplishment to present the issue as a matter of social separatism.
The "we" most certainly requires an understanding of being "not them", otherwise the entire discussion of identity politics and equal rights would make no sense. Either one can demand equal rights for one's particular group, *OR* one can demand to be counted as member of one of the existing privileged group. The latter strategy was successfully applied by many closeted homosexuals who made any possible effort to appear belonging to the privilleged group of heterosexuals - they entered heterosexual marriages, produced children and presented themeselves in any other social facette as "straight". It's equally understandable and disgusting to see some Gay people returning to these tactics and trying to persuade heterosexuals to see them as "straights honore causa". These straights h.c. often tend to publicly express their indignation about other (too colourfull) gays as opposite to "normal" people.