School frustration

So in school, i guess that it is customary for teachers to assign reading assignments that would be use or tested on in the following classes. I have a problem with this, or else i wouldn't be writing on it. So they are telling me that i need to go take time out of my busy schedule to read on some subject and use it in the class. Well my question is WHAT THE HELL AM I PAYING FOR THEN? If you aren't teaching the necessary stuff and i have to read it myself what am i doing there? The amount of info that some one gets out of reading the book only takes like 5 mins to cover and most of the time they have to go over it again because everyone forgot it. In addition teachers were in the same place i am in, they know that a student's time is over taxed and they don't have time to read 70 chapters. Professors y'all need to do your job because i'm there to learn from you and not the book on my own time.