I disagree. First, it's his money and he's the customer. Customers ultimately drive product requirements, not vendors or consultants, and vendors that meet customer requirements better get the sales and become the market leaders, regardless of who thinks the customers are wrong or not.
Second, the NEC looked better to him. Right out of the box. And it still works really well.
Nothing at all wrong with any of that.
Third, a tune-up is a more accurate comparison than adjusting the mirrors. The position of the mirrors does not affect the core performance of a car. The color of a monitor does affect the core performance of the monitor.
And you don't need extra calibration tools to adjust mirrors in an auto. Doing that takes matter of seconds. You do need extra calibration tool (software, hardware or both) to adjust color in a monitor. Calibrating a monitor takes considerably longer than adjusting mirrors in a car.
Me personally, if there are two products of equal quality and one works out of the box and one doesn't, I'll take the working one any day. But different strokes for different folks. If you like tinkering, it's perfectly reasonable to choose the product that needs tinkering. But that's a choice not everyone is happy with, and feeling that way is perfectly ok as well.