Most colleges have plenty of classes about different aspects of Western civilization, including everything he mentions in the fifth paragraph, so this is really a question of what should be required for general education. Everyone has different interests (for example, I would really enjoy a big-picture class about Western civilization, but I can see that a lot of people wouldn’t), so how can schools create a general education program that gives everyone some common ground without alienating anyone?
Also, if students are studying Western civilization less, it’s probably due to careerism more than anything else. Despite the hand-wringing, it’s not like people are earning “studies” degrees in spades either. The most popular major is business.