Never get me started on racism in Islam because how Arabs  South Asians treat their black counterparts is generally disgusting
Do they treated other races badly?
They are horrible communities and only Arab people are capable of treating people well because of their culture. They are also the only group taking slaves in south asia.
While some Muslims can be racist, some are not and assuming that all of them are racist is wrong. You would be upset if people assumed you were a racist based on your religion.