Discoverability certainly is an issue with vim – but it isn't really with Premiere. What I was alluding to with vim was more the combinatoric aspect of powerful tools. Creating software that solves one specific problem with a beautiful UI isn't that hard – creating something that solves a very broad range of problems is infinitly harder, because you need to give the users a language in which they can tell the machine what they want. That "language" can be shortcuts and chainable commands like in vim or it could be graphical, using a timeline, context menues, drop downs, symbols etc.

However: the more expressive this language has to be and the more problems you should be able to solve with it in precision, the steeper the learning curve will get. And as with spoken language, there are hard to learn languages that let you express certain aspects very precisely and there are simpler languages that might be easier to learn but make it harder to express certain things (e.g. "You" in English vs "Du"/"Sie" in German vs. all the formal variablity of Japanese).