Technical knowledge and people skills are different things.
If someone has taken the effort to contact you, they likely already have a bad first impression of you. If your response is focused on "educating the customer" or is too conscious of what's fair for the business itself, it will probably not impress.
Great customer support is the kind that might result in a customer sharing their interaction with friends or social media. The support the author mentions in this post isn't likely to do that.