It's not disagreeing, it's the entitlement on display. There's nothing wrong with "I wish the discounts were bigger". The problem is that he appears to be foaming at the mouth about how they're not good enough for him.
Even that being the case I don't understand why the foaming bit. If you don't like the prices then don't buy the product. Isn't that what consumerism is all about? The choice as to whether you buy or not...