Study Group

For whatever reason, Harry gets a hold of the old homework/syllabus/tests of somebody from an earlier year, and notices that it's extremely different than the work they're doing in class. So he goes to Hermione, and she's all, "Why do you think I'm making such a big deal out of the OWLs and NEWTs? We're not being taught half the stuff that's on the test!" Realizing this, they start a study group which begins as just them and grows. Ron never joins and thinks it's stupid. But why has the curriculum changed? What do the professors think about it?