I didn't realize you were so ideologically wedded to democracy. Why should a majority have free rein to take away the rights of the minority?
That isn't the definition of democracy. What you are describing is an authoritarian state with majoritarian support. The majority of people in China probably support or are indifferent to what's going on in Sinkiang; that doesn't make China democratic.
When people talk about democracy, they're talking about a representative government with free and fair elections. In these countries, the rights of the minority are safeguarded either through a constitutional/legal protection of civil rights, or through robust government programs.