It's not simply about what's "boring" and "not boring", which is subjective anyway. It's about tangible vs. intangible. Most school coursework is intangible & lacking context; grades have little to no bearing on real-world performance and book knowledge very often doesn't translate into solving problems & generating solutions for paying customers.
There are plenty of people who love learning but who just aren't interested in academia, in being told what to learn, what to spit out on some trivial assessment etc. And the fact that these people can motivate themselves enough to blaze an autodidactic path as opposed to relying on dictation from other people ought to be proof enough that those are folks who have more than enough motivation to start a company.
If I see somebody who graduated summa from a decent school, I instantly know at least one thing about them: they're good at identify what the customer wants, and delivering it. You simply can't graduate top of your class unless you find a way to give dozens of (sometimes unreasonable, often unclear) people what they wanted, when they wanted it.
There are plenty of people who love learning but who just aren't interested in academia, in being told what to learn, what to spit out on some trivial assessment etc. And the fact that these people can motivate themselves enough to blaze an autodidactic path as opposed to relying on dictation from other people ought to be proof enough that those are folks who have more than enough motivation to start a company.