Why do Shias beat upon themselves on 9/10 muharram

Re: Why do Shias beat upon themselves on 9/10 muharram

Narrated 'Abdullah: the Prophet said, “He who slaps his cheeks, tears his clothes and follows the ways and traditions of the Days of Ignorance is not one of us.”

shias typically derive rulings such as fulan ran over burning tents so it is ok for them to continue their zorastarian practice. the marjas have complete control and they’ll rule according to what history they have been told or read leading ultimately back to their own desires. obviously i have no problems with someone loyal to oldpersian culture but they rebranded as shia islam, which is problematic very much since we have obligations to islam