Quite different of a mentality of a mainlander than a chinese expat.The Han nationality is a part of the Chinese civilization, but the Han nationality is not equal to the Chinese civilization. These Han netizens only rarely come into contact with the surnames of ethnic minorities, they are not Han supremacist.
In fact, of the eight ancestors of the Chinese civilization(三皇五帝), only five were Han, and three were 东夷 and 九黎. The Han nationality is only the elder brother of the Chinese civilization, not all of them.
I respect those who consider 56 ethnics to be chinese, and not just Han.
Han supremacists will just end up like Song or Ming, conquered by those they deem barbarians.