the reason why the central gov can be so aloof, is because they know this fire is contained within HK, it will not spread to mainland because there is no support of them, and the more violent it is, the more the mainlanders will know what unrestrained neo liberalism can bring to them. As for HKers, the longer this going on, more people will feel fed up with it. At that time, they will beg China to come to return them to normalcy. Until then, China can wait and let the shit simmering in HK.