The only counter-argument that comes to mind for me didn't form itself until I had read this last paragraph a few times.
If your identity marker connotes tolerance then it hopefully has the opposite effect. Insofar as the experience of marginalization promotes empathy such identities might be good evidence for intelligence, and I do think individuals who feel oppressed or marginalized tend to empathize with others who suffer for different, marginalized identities.
These identities will only breed stupidity if the individual feels a competition for scarce resources that overwhelms their empathy, whence the perniciousness of the belief in zero sum attention economics as a greater threat to activism than inaction, ignorance, and exhaustion.