The culture of a platform starts from the top. Go on any forum or social media site or Group, and have a read around and you will see what calibre of leadership is in place. If they think scandal and arguments and trolling is good for business they will allow it. If they can’t abide un-constructive commenting and don’t want nasty-minded cowards on their platform, they will actively get rid of those users.
Twitter are beholden to shareholders with no interest in the community their company serves beyond how much money they can extract from it. A good dose of scandal has obviously been deemed good for business, and the (hopefully) embarrassed leadership have no mandate to make Twitter a safer place for all.