Magic users are things that know a lot of the right complicated stuff.
The more stuff you know, the easier it is to learn complicated stuff.
The more people there are who know stuff, the more people there are who (could) know lots of stuff.
Industralization requires having people who know how stuff works.
Lots of people. Lots of potential (if unlikely) future magic users.
Magic users are exclusionary, they don't like magic users.
You ever have a neighbor magic user? It's awful.
Their tower might be taller then yours! You have to keep adding to it, just in case.
And you're constantly writing dissertations at them, it's this highbrow form of poop slinging.
Believe me, nobody has the time for any of it.
Speaking of not having time, you have a bunch of nobodies under you to save your time.
They're aplicat... associa... hmm. There's a big word for it. Starts with A. Maybe Ap? You don't like that word.
They always expect you to remember their names for some reason. And they constantly ask questions. Have fun with that!
And you have to keep a really close eye on them. Almost wastes more time than they save you.
Be careful, every now and then you discover an extra magic user that lives in your tower.
In YOUR tower!
It's great at first, saves tons of time. But sooner later they start getting funny ideas, like maybe it's "their tower".
Their tower!? Messy stuff, dangerous ideas. Sooner or later nobody has a tower. Or at least you don't. And that's just terrible.
Every magic user I've met lost several towers that way. Building a new tower takes forever.
Believe me, I distinctly remember waiting through building all of my towers. Except my first, I guess.
And anyways, you get enough people asking questions and they're bound to start asking tricky questions.
Like, "Why do magic users always have towers"? The only things I know who know that are magic users.
If they knew, that'd make them a magic user, right?
So anyways, magic users don't like industrialization.