Language and culture might outweigh government for most people as reasons to stay versus move.

Certainly. Essentially, this is a problem of incentives vs. costs. At present, high costs (such as language and culture barriers) prevent a socialist from Singapore and an economic conservative from Sweden from switching places. Likewise, a liberal from Huston and a conservative from San Francisco might stay put because of insufficiently high incentives (thanks to the central government the practical difference between living in Texas and California is not that big).

However, the situation is different when small territorial units within one mono-lingual country get real autonomy (e.g., the provinces of Holland and Zeland in the Dutch Republic). Then the competition for people becomes a real factor in their politics.