Craftsman tool vendors no longer warranty items that our fathers got replaced for free. It requires a lot of profit margin and a big chunk of the market's sales to finance the largesse of fixing anything regardless of original purchase. Some do, some don't, owners change hands, and in some respects there is simply too many less than reputable claims which cause reconsideration of the entire policy at times.
Given the historical nature of all customer service, we are lucky to get what we get. The actual intent of having that department at all is that it's less expensive to repair a few firearms than make every single one absolutely perfect. If there are 10,000 in a series sold, and your potential return/customer reject rate is .01%, that's still a few hundred guns not satisfactory. Easier to have those disappointed fixed than spend a exponentially higher cost inspecting and rejecting them - it drives the overall cost of the gun up even more, a bad thing in a highly competitive environment.
Some smaller makers do exactly that - accept the higher scrap rate - and charge accordingly. If you are paying $1,100 for an all metal gun and expect absolute perfection, bounce that off the makers of that same type of firearm who charge $3,500. You get what you pay for - less defects, higher quality fit and finish - you don't get 3X more deadly a gun firing a bullet 3X faster holding 3X more ammo or 3X safer.
For every doubling of the guns price you get less than 50% improvement. To always get an absolutely perfect gun, no matter what, every single time - expect that to cost a lot more. $10,000?
In terms of production and quality, guns aren't much different that cars - we already know they do a better job on the line certain days compared to others, and certain cars can be either an absolute marvel straight off the line, or later found to have severe aerodynamic and handling issues - like the Audi TT.
So, up the price double and you have 50% less chance of defects - how expensive is that perfect Glock going to cost? I've heard of aftermarket builds with substitute parts - alloy frames, no MIM - costing over $2500. Which one is the real example of perfection?
I'm going to suggest that even bespoke firearms custom made to the exacting specifications of the most critical owner won't past muster after ten years. Which those owners prove by ordering more.
The whole thing in a nutshell is the customer has expectations and they may or may not reflect the reality of mass producing a firearm for commodity sales at the Low Price Guaranteed. Sometimes we just ask for too much. Hand fitted Winchester bolt guns for $150 aren't coming back.