(1) One of the most important ways that cultures differ is in their normative biases.
(2) When composing a multicultural Venn diagram, the intersection can only contain non-contradictory elements of the cultures being combined.
(3) Norms are often contradictory in a way that, say, food is not. (Food, and music, the most commonly cited blessings of multiculturalism, are non-normative. To the extent that music is considered normative, it becomes subject to cultural exclusion.)
(4) Thus multiculturalism preferentially strips away normativity from the public square, to be replaced only with such artificial norms as are necessary to suppress traditional normative expression.
(5) Every acculturated human is normatively inclined to do, and publicly to favor, the things that his culture prescribes — and to avoid, and publicly criticize, what his culture forbids. (Even though normative prescriptions and proscriptions must, in principle, subtract absolute liberties, in an organic culture they do not do so in a meaningful way, because we do not feel our liberty diminished by compulsions or prohibitions regarding things we would or would not do anyway.)
(6) All of this is suppressed by multiculturalism. Perceived liberty is diminished, because we must not publicly say or do things that we would otherwise do.
(7) This means that the public personae of citizens of a “multiculture” are reduced to only those norms and qualities that are in the intersection of the Venn diagram. The more cultures we mix, the smaller that intersection gets, until humans, in their public role as citizens, are reduced to the basest sorts of commonality.
(8) This causes an increasing tension between every citizen’s public and private persona, decreasing his natural connection to the community and ambient “culture”.
(9) Thus, by suppressing the public expression and accommodation of ambient and internalized norms, multiculturalism breaks down organic social order and cohesion; it can only be replaced by a top-down, external order that acts on citizens only as instances of the stripped-down humanity described in (7).