"From a business perspective what is the incentive for twitter to solve such a problem?"
From a business perspective, being perceived as a platform for trolls and harassment is really bad for the brand - even if its a minority of users who are causally throwing out rape threats and other abusive garbage at other users, they are incredibly toxic.
From a business perspective, being perceived as a platform for trolls and harassment is really bad for the brand - even if its a minority of users who are causally throwing out rape threats and other abusive garbage at other users, they are incredibly toxic.