I don't think that's the original quote, but rather came later to try and improve the clearly flawed quote. Searching, I found https://grammarist.com/phrase/the-customer-is-always-right/, which says the original quote is the rather uninspiring "Rule number one: the customer is always right. Rule number two: If the customer is wrong, please refer to rule number one".

That said, I do agree with you completely. I think the quote is just so obviously flawed, as customers abuse the heck out of it. Treating it as applying to aggregates makes way more sense. e.g., if customers want a pink doodad and you only sell doodads in black... well, then you're wrong and should start selling them in pink.

As a corollary, I also like the quote that has been often attributed to Ford (but checking, it seems unproven if he actually said it), "If I had asked people what they wanted, they would have said faster horses." I like that quote because customers often frankly don't actually know what they want. I've had countless times myself where I didn't know I wanted a product until after I learned about it. And myself, I'm a software dev. This quote constantly applies to my field. The idea of users not knowing what they want is an extremely popular meme in the field (example). Users often need expert guidance to identify what they actually want and what a practical solution might look like.