I've done a lot of quality management work over the years. One interesting thing I've learned is how to look at products and improvements. If you are responsible for a product being able to carry X loads and have a service life of Y years and you design it so it can carry 1.5X loads and have a service life of 2Y years you haven't "improved" it. In fact you have missed the product requirements by a fair bit and if there are any additional costs for that you'll get some flack from your boss.
High/excellent product quality is not exceeding the product requirement it's meeting them very reliably. The one area where that is not true is cost. No company is going to set a low end limit on manufacturing costs.
Coming back to King hubs...Andrew's thinking about them as a multi-decade purchase. But, maybe [I have no data to back this up] the original purchaser of a King hub only keeps them in regular service for 3 years in most cases and then uses them sporadically for another 3 years before getting rid of them. In that case a hub that lasts 5 years of regular use might meet their customer's needs just fine. If that 5 year hub was cheaper to make than the 10-20 year hub it would be "improved" from the company's perspective without harming the majority of their customer base.
When people chat with me about hubs they are interested in cost, colour, weight, width options, brake mounting options, strength, POE, but nobody has ever asked me "Will that hub last 20 years?"