Although it doesn't apply to the people of today historically it may have been very bad. It might have something to do with what mariusj said although I'm not quite sure entirely what is meant by the viewpoint of unworthy that was held by the elites against the imperial clan. Anyways if they weren't making fun of the Tang emperors' ethnicity then they were probably refusing marriage on some other political grounding. It is weird to refuse marriage to imperial clan since that would improve your modicum holdings of power simply because the emperor wields the final authority of state.
The Northeast Aristocracy that Mariusj is referring to claimed they were the pure descendants of prestigious Han Dynasty clans - upholders of Han Chinese tradition with unblemished lineage, who had refused intermarriage with the barbarians of the Age of Fragmentation in order to preserve their noble lineage. They held the Northwest Aristocracy, to which the Tang emperors belonged, in disdain because they saw them as socially inferior clans that happened to gain a little political power, though the idea that they were semi-barbaric, since they had mixed with the Wu Hu, might be a contributing reason. The early Tang emperors were furious over this, but the Northeast Aristocracy was influential enough that destroying them was a no-go, and so more subtle means were adopted to attack those clans, like downgrading them in a list of most prestigious clans.
Qing was a little more complicated I think since they were themselves paranoid to a very large degree. Literal inquisitions by the emperor to assassinate entire families of one author for his seemingly unkindness in words against a regime headed by Manchu ethnic peoples.
Qing was different in the sense that it was an explicitly ethnically-oriented regime. The Manchus may have invented themselves in the heydays of Nurhaci, but they recognized, upon entering China, that they were an ethnic minority and that much of their political power came from being an ethnic minority. It was by maintaining their ethnic separateness and the Manchu identity that the Manchus were able to keep political power in their own hands and away from the civil bureaucracy that both the Ming and the Qing depended on to run the country. Ethnicity was thus not only a sideshow but a main component of Qing rule. The Manchus were an ethnic entity, bound by adherence to Manchu customs, genealogies, and histories, upheld by Manchu-specific institutions and laws, and which looked to the Han as a separate group that they must not be absorbed into.
The Manchus were never "assimilated" during the Qing.
Edited by Eidolon, 16 September 2011 - 11:58 PM.