Ask HN: Why teach theories when they are not applied in reality?

Maybe it's just me that is unlucky with companies which I worked/work for but as I see and get from some friends working in another companies (all fields included) theories are not working.

Now I'm wondering what is wrong ? Schools or companies ?

The problem it's a spend severals years learning theories from my teacher, practice it and once you're working for a company you just face de reality and nothing work like your learned.