The Han people value the principle of having a just cause.
Or rather, since ancient times, the Han people have been accustomed to taking the moral high ground in their actions.
Fourth Master's arrangement to worship at Ming Xiaoling Mausoleum is meant to convey this message.
Who is buried in Ming Xiaoling Mausoleum? Zhu Yuanzhang, the founding Emperor of Ming Dynasty.
In truth, from a moral standpoint, the notion of overthrowing the Qing to restore Ming doesn't hold water.
Because it wasn't the Qing Dynasty that destroyed the Ming, it was Li Zicheng the Chuang Wang.
More accurately, he didn't exactly obliterate it, but he did take over the Forbidden City and forced Emperor Chongzhen to his death. In ancient times, when an Emperor was driven to death, wasn't that virtually tantamount to the dynasty's downfall?
