There are many businesses for which certain times of the year are when they make most of their money.
For example, you probably aren't going to find a lot of people seeking out a fresh Christmas tree in July, and it takes a special kind of individual to want to rent a sun lounger on the beach in the middle of winter. While some businesses are strictly seasonal, others are year-round and make their biggest profits in different seasons. Most types of retail are the perfect example of that throughout the period from Thanksgiving to Christmas.
While a rush is great news financially, the logistics of it can be stressful to work through. The more customers there are, the more likely it is that mistakes will occasionally be made, and things will be missed. As a result, good customer service is never more important than during the busy times. Owning up and trying to rectify an issue when something goes wrong is an important display of integrity.
Unfortunately, there are places where this simply doesn't factor into their business model. While it may be true that there is a type of entitled customer that it is better to disappoint than cave in to, there are plenty of others who just want to have a fair deal. If they have spent good money on a product or service that has failed to deliver that, it is only natural that they will want some kind of compensation for what they have experienced.