Putting a Netflix show on DVD and selling it is absolutely illegal unless they have a distribution license provided by the copyright holder.
It would be legal after copyright expires (in the US, copyright exists for the lifespan of the author/creator + 70 years). Keep in mind that the US has stricter copyright laws than most of the rest of the world.
For other items, like physical functional items, reproductions are generally legal unless the item is patented. And it would still not be legal for the reproduction to also reproduce any registered names or trademarks associated with the original. Example: you could legally reproduce and sell knockoff Nike Air Jordans as long as you didn’t use the Nike swoosh or any likenesses of the copyrighted artwork. For items that are patented, or patent pending - making and selling reproductions is illegal - and for most patented items the reproduction doesn’t even have to be identical for it to be infringing, just replicating the functionality is probably infringing.
A mix of “willfully ignorant”, “narcissism”, and “intolerance”.