For the last week I’ve been playing with Susty and building a specific child theme around it - thankyou for linking it. I absolutely love the minimal philosophy behind it and I love the idea of this being bundled with CP as the default theme.
The only things I’ve personally changed in my child-theme (apart from some basic colours) are adding a more traditional, responsive menu through CSS alone and adding a Widget area to the footer (Though I’m sure somebody could do better when it comes to keeping things minimal). It occurs to me though that potentially little layout tweaks could also work as plugins - which would be a beautiful way to support a core-theme: minimalist changes you either add or ignore, nothing with too many features/options that people may want to disable.
Incidentally, the last work-experience kids we had in my work were doing courses in either general IT or web design and they had modules using WP as a basis. Though they were young and obviously still learning, some of them definitely have some bad practices that have been if anything exasperated by the ability to add plugins or themes of a wide-range of quality and function on the fly. So I doubly love the idea of this being bundled (as well as core-plugins) in that it not only makes sense but encourages much better practices for those using it as a learning tool (especially as somebody who is still learning myself).
Edit: The other themes mentioned are looking great as well though I’m yet to play around with them. I wouldn’t be too averse to something like Generik being bundled either.