The 39th issue of Bennett's Five Links.
Only recently had I learnt though there is some conjecture on whether that expression has been truncated down from the slightly longer expression, ‘the customer is always right in matters of taste’.
This longer saying makes much more sense to me. On subjective items such as style, taste, fashion etc - the only opinion that counts is that held by the person giving up their money. If the diner says the meal is too salty then yes, what they’re saying is that the meal is too salty for them. It’s not necessarily a criticism of the chef, who may be preparing the meal for the average palette. But the diner is the person paying the bill - not the phantom average person. And so the meal is too salty.
Is it fair to chef? Absolutely not. But life’s not fair - and adopting this approach will result in a happier customer, which is better for the chef anyways.
Do you want to be right or do you want to be happy?