Very insightful post. I've noticed at times intrinsic motivation will be put down by society as 'useless' but not everything needs to be useful to society to be meaningful... An example in my family would be my brother who is learning a few languages, including Luxembourgish and Armenian, with plans to learn more 'obscure' languages. My parents, and extended family always joke about it, and will tell him to learn Spanish or German or something that he will use in regular situations, but he feels drawn to these languages.
I think intrinsic motivation is much more interesting and meaningful, though there must be a balance, because you do typically need to be motivated by foreign forces as well. As important as our intuitive, natural motivations are, we must find a healthy balance and also be productive. Ideally, you can turn your intrinsic motivations into something that benefits society and in return you are rewarded for... That is what I still need to figure out how to do