Or maybe you should read the books first, as they tell you more then the movies...

-muggle studies is exactly that, the study of muggles and their culture... being dated by almost 50 years, it ain't of use by anyone, and conservative purebloods (yes, the kind which would decide which lessons are provided) would rather kiss dumbledores feet than make it non-optional...

-mostly, wizarding children are homeschooled, so the parents are responsible to make sure children can read, write, count etc... further education herein is not part of the regular plan, muggle literature isn't worth reading (as decided by the pureblood community), and wizarding fiction is limited to childrens books and cheap romance novels, advanced maths are covered with arithmacy, and sciences are obsolote (as magic defies al laws of science)

So you are getting worked up about nothing, wanting to get whole inclusive and such... the wizarding world is utter rascist, not against other races, but in blood, and trying to repair such things is really going AU...