Why do most books written by a Han Chinese in February River praise the Qing Dynasty?

It is normal. There is no rule that Han people can't sing praises to the Qing Dynasty. Most officials in the Qing Dynasty spoke Chinese, so they kowtowed to the Manchu emperor.

Besides, how do you know that February River is Han Chinese? Do you know anyone else? How do you think you can tell if the other person is Han Chinese? What is the definition of Han people?