Although the author is a bit harsh, I tend to agree with him on the aspect that Amazon is largely creating second rate products and ultimately wasting a lot of shareholder money (their inventory write down on fire phone inventory was $170M). The markets have been punishing them for their tactic of throwing it against a wall and seeing if it sticks. Ultimately, I think what allows a company like Apple to get ahead was…
But in reality, it's not the hits that Amazon counts on--it's the recurring revenue of Prime and Unlimited subscriptions and loyalty around lots and lots of low-margin purchases. To keep those memberships coming, you don't need to be a hit machine--you just need to keep offering incremental useful value, mediocre as it may be alone, to add value to the subscription.
I think that's the angle. It's not that Costco hot dogs are the best hot dogs in the industry for $1.50 (or $4.99 rotisserie chickens, or car buying services, etc.), it's just that these items add enough value to enough peoples' Costco experience that they renew memberships and spend a lot of cash on low-margin stuff.