Despite being designed to be cheap (er) to make, it should still be remembered that the 870 was sort of a wunderkind when it showed up. Yes, it may have been another step in the history of the the sporting "punch press gun," but as a complete package it sure impressed a lot of people at the time... maybe not the owners and users of high-grade shotguns, but for the man of middling means, it was the right gun at the right time. It took various changes of management and bean-counters years to cut corners in the small details and give the thing a black eye.
ALL the big names screwed the QC pooch for miniscule savings, some of them before the second round of the World Wars, others after it. The various post-DuPont suits at Remington just seemed particularly clueless about how to save/spend money. Sponsoring NASCAR teams and licensing the brand for use on cheap POP merchandise didn't work out so well.