I'm the same way but I think people like us tend to be heavily over-represented on HN and probably represent a small fraction of the total audience. Similarly, I like to watch YouTube videos for specific technical content where the vast majority seems to prefer pop culture and cat videos.

A couple of other personality types / situations to consider:

1) Some people treat learning the way they treat a workout... procrastination is the path of least resistance. So metrics like course completion % 'gamify' it for them to give them the push they need to keep motivated.

2) In the business world, think of the times someone has said 'I'm not trained in that' (or something along those lines, often to try to get out of doing something) and the boss says 'well, go get trained in that.' Course completion is a thing that can be shown to said boss to 'prove' they learned something. While self-learners would tend to keep their mouths shut about not knowing it and say 'sure, no problem' and then go find whatever training materials were needed to learn said thing.