The argument, "because active classes would be boring if they were active" sounds to me like arguing to not have fishing, writing or any activity in a game. Because that is boring and takes a long time to do in real life. But this is not real life, this is a video game, so make the classes fun just as you made fishing and writing fun to do in the game.
Have sims learn different skills, give them the possibility to work in a group to solve a case, give us the option to take notes so we can review them later, have different progression bars, give us the option to choose what to learn during a class...
