I think that such people could probably benefit greatly from some tutorials that explain how to do some common things, such as how to make scenes, how to make windows, how to add options to menus, etc. Maybe it could be a plugin creation series that starts out small and culminates in the creation of an actual useful plugin (like a Monster Encyclopedia or something).
As far as I can tell, if someone new to the scene wants to learn to make MZ plugins, their options are either:
A.) Read the code for the entire engine and hope that they're able to wrap their head around the entire system.
B.) Read MV-specific tutorials and hope that they can figure out which parts are no longer applicable in MZ.
Option B wouldn't be so bad if there was a comprehensive list of changes between the two engines, or some type of porting guide or something, but for some reason, no such thing seems to exist (as far as I can tell). And option A is just too overwhelming and/or too much of a hassle for some people.
I pretty regularly see people claim that MZ has a severe lack of plugins. I also see a lot of people claim that RPG Maker is "limited". While I think that both of those claims are largely unsubstantiated, it doesn't change the fact those are common beliefs that people seem to have, and that those beliefs are part of what's stopping people from buying MZ.
I think that maybe if you could give people a bit of a leg up, and help them learn to create plugins, it might help alleviate people's perception of those issues a bit. It would help give the people who are still clinging to MV the confidence that they'll be able to either make the plugins that they need, edit existing plugins to do what they need, or port MV plugins over, so that they don't feel the need to keep avoiding the switch.
And I think that if we could lower the barrier of entry to making plugins just a bit, more people would do it, and people would start to adopt the mindset that they have the power to bend the engine to their will--instead of feeling restricted to just using only what they're given. I think this could help alleviate the common claim that RPG Maker is "limited".