For one thing, not all of the things you said must be mastered, vim is plenty big enough to support various ways of working. E.g. I never use the arglist.
For another, from a pedagogical perspective, there's different levels of "mastery", and there's nothing worse we can do to scare off people trying to learn a new editor than to tell them "oh, no, to be considered a real master you need to put in months of learning".
For one thing, not all of the things you said must be mastered, vim is plenty big enough to support various ways of working. E.g. I never use the arglist.
For another, from a pedagogical perspective, there's different levels of "mastery", and there's nothing worse we can do to scare off people trying to learn a new editor than to tell them "oh, no, to be considered a real master you need to put in months of learning".