I don't think this is always true, if, as a business you can charge more, lower the crowds which would reduce maintenance costs than maybe. You wouldn't really care how many are coming as long as your profits are the same or more. I am not saying this is what Disney is doing, I am just saying that this is a possibility.
I don't know how common it is for consumer businesses, but with business-to-business, it is pretty common to review your corporate clients to see which ones are either:
1. out and out unprofitable - there are some cases where you're actually losing money on a client because the product and resources they consume are greater than the revenue they generate.
2. super-low margin - in this case you're making money on a customer but you're barely breaking even, so sometimes you'd do better to get rid of them and replace them with customers on whom you can make higher margin.
At one of the companies I worked for, we reviewed the client base on this basis, figured out which clients were money-losers or barely-breakeven, and then raised prices a lot on those customers to either convert them to profitable customers or part with them.
Actually, thinking about the direct-to-consumer businesses, you see this kind of behavior sometimes when you have "unlimited" plans and have customers who consume more than they pay. So for instance cellular phone and data providers sometimes have this problem as well as unlimited web hosting companies or unlimited backup providers.
I think I also recall hearing about companies like Home Depot doing something to try and rid themselves of customers who buy equipment then return it used too often.
I do agree though that you don't see across-the-board reduction in customers being an end goal for a business. All of the above examples are targeted. The equivalent in Disney's case is probably season pass holders who come all the time but don't eat on site or buy souvenirs. At some number of visits such a customer might end up being a money-loser for Disney, or at least so low margin that they'd rather see what they could do to replace said customer with a more profitable one. As an alternative, they could see if it is possible to turn that customer into a profitable one - perhaps by lowering the price of food? Nah!