He is troubled with Culture as noun, for its implication that culture is an object, thing or even substance. This substantialization brings culture back into the dsicursive space of race – the idea it was designed to combat. Also, if seen as mental substance, culture appears to priviledge sharing among unequal partners – the weaker is marginalized. cf. Western civilization and Islamic barbarism.
He finds the concept of difference most valuable, more valuable than the concept of culture as property., therefore culture is best used as device for talking about differences.
Only these differences that set the ground or mobilize group identities should qualify as cultural differences.