We can only guess their motivations and who pulls their (Twitter's) strings behind the scenes. I am not sure that most of us here will ever find out.
I don't understand this perspective, but I guess my own is built from experience. We can never know exactly what Twitter discussed internally before taking this action, but there is lots of external evidence and signals as to what happened. It's unlikely to be different from the action taken by most other corporations with legal teams.
Small organizations with outside counsel can surprise us with their decisions since there are more concentrated opinions and higher risk taking. Perhaps GitHub and youtube-dl is the only outcome that has surprised me recently.