In addition, it is not realistic to have the five prayers when you work at school, as police officers, as government officials and etc. In addition, there are those non-muslims as well. If you think it is unfair, that is your opinion. Talk to the Chinese government. Chinese government is quite sensitive to those religion interference and we strictly have state and religion separation limitation. Whatever you do at your home or mosque is your freedom as long as that is not against Chinese Laws. In public places, offices and schools, we just won't allow those religious rituals to happen. As simple as that.