The approximate cost of attendance is $14,068 base tuition, ~$12,874 for living in a dorm. There are currently 37,581 students attending the school. According to an older budgeting plan from 2013-2014, their total revenue was estimated to be $2.35 billion, and that's an old estimate. Costs of tuition have since gone up.
It's true that they use a good portion of that on necessary academic expenses, but my argument is that the cost of subtitling those pale in comparison.
Also, they're not going to be spending "hundreds of millions of dollars closed captioning movies." If you've looked at all, you'd see that they're all lectures from their own campus that were placed online give people free access to their courses and materials. It's not fucking movies. That doesn't even make sense.
Now, they're restricting to students only; cutting off access to excellent learning material that people around the world use to improve their knowledge.