(Author here again) I appreciate your point here! It's true that "wizard" reminds me a little bit of being called a "rockstar," which I have always had a distaste for due to the above-mentioned ego thing. I elected to use "wizard" because I find it to be a useful and interesting metaphor in light of my own personal love for RPGs and fantasy, and because I was really inspired by Julia Evans' use of the term to de-mystify learning. I think of it as a rhetorical device, and nothing more.
(Author here) That's actually a real conversation that happened over a year ago, and I ended up becoming technical lead on the project later! No signs of firing yet. Not all companies are too lazy to care about their employees. It is, realistically, the smartest financial choice to invest in growing the people you hire instead of just throwing them away and hiring new ones every quarter.