I am in finance. Graduated from Wharton.
I did a little analysis on here arguing the same point. Disney's operating margin at theme parks is around 18%. Media networks (TV) is around 33% and studios (movies) is around 28%.
For comparison, Apple's operating margin is over 30% and I'm sure you've owned an iPhone at some point. Or Visa. Ever swipe your credit card? They make around 70% operating margin.
Remember, operating margin is not profit. It won't include things like taxes, interest expense, etc.
Bottom line. Theme parks make decent money, but it's a somewhat low margin business due to high labor costs, maintenance, expansion, etc.