2) The goal of a game designer is to create fun experiences that you actually want to do. If game designers announce they're including scripting for the purpose of automating repetitive tasks, it would probably feel embarrassing to them because any boring and repetitive parts of their games should feel like kind of a personal failure on them.
3) I'm not a full-time professional game developer, but I'd imagine that trying to implement some kind of highly polished scripting that's user-accessible represents a significant additional effort in many cases for very marginal financial benefits. It's not just building this feature that would be required, but you'd be introducing a potential new security/stability risk that would need to be extensively checked, as well as having a big system that needs to be documented and supported for users.