As a westerner, I cannot agree with this. I think you have it the other way around. Until the late 19th century, Chinese thinkers saw themselves and those around them largely in cultural terms. They themselves were the "inner, civilized" people originating from the Central Plain of north China who called themselves Hua. The others were various "outer, barbarian" people. It was only under the pressure of foreign imperialism that the Chinese scholars and officials were compelled to start of thinking of their country no longer as a cultural sphere, but rather in political and geographic terms as a nation-state. It was principally Liang Qichao who was responsible for the redefinition of China from a civilization (actually the only civilization!) to a territorial state (among many).
The Western take on the Han is based largely on their experience with the Qing multi-ethnic empire, that was divided into several regions, of which Han populated China was one. The other 4 regions were Manchuria, Mongolia, Turkestan and Tibet. All inhabitants of these regions owed equal but separate obeisance to the emperor, which was evident from the fact that they were administered separately. Whereas the Han were governed by the civil bureaucracy and the Manchus (really all the banner-people) by the Eight Banners, the Mongols, Muslims and Tibetans were subject to the Court of Colonial Affairs.
It is interesting to remember that the early republican revolutionaries saw China as land belonging to the Han people, in other words China proper where nearly all residents were Han. The Manchus had no place in this China, and were to be expelled. They echoed the old revolutionary slogan of "Oppose Qing and restore Ming". As Zhang Binglin intimated, the appropriate refuge for the Manchus was Manchuria, their ancestral homeland, where they could create a nation-state of their own. The Japanese later tried to make that a reality.
The PRC engaged in Stalinist inspired social engineering, proclaimed itself a multi-ethnic state and exploded the originally 5 officially recognized ethnic groups into 56. The Muslims alone were split into 10 different groups, and the term "Hui" came to be reserved for the Chinese-speaking Muslims. On the other hand, the Han underwent a minimal subdivision even though distinct groups such as Hakka and the Subei people could arguably have qualified as ethnic groups. Interestingly, the Manchus too exploded. What used to be one people in the early Republic, became six: Xibe, Daur, Evenki, Oroqen, Hezhe and the Manchu.