He's not even just not personable: he has no presence. I feel like he'd be the kind of teacher who just droned on for hours, got pissed at students when they interrupted them, and made everyone feel stupid if they didn't understand, and then expected them all to do perfect on his bizarre exams.
Not to mention I highly doubt Connor would be able to deal with the other things that come with being a teacher. I doubt he'd make any effort to remember his students' names, or interact with them. He would probably find grading to be too stressful. And I don't know that he could handle teaching multiple classes.
Powerlevel alert: I graduated high school the same year as Connor. I'm a first-year master's student, and I'm responsible for teaching 3 classes between Thursdays and Fridays (the actual professor does the teaching on the other 3 days of the week). I just got done with Friday's session. And there is no way in hell Connor would be able to do that, at least not at his current state. It involves so much more than just teaching, and teaching itself is a skill that I don't think Connor can possess, at least not with significant training.