I'm going to take a stab at this.
>Skip the spider.
Maybe an exhortation to not think of being a customer of Amazon like being a spider in a web. Spiders know where the next meal is by vibrations in the fabric of the web, which if we imagine the negative comments as vibrations caused the receipt of a skeevy item from a seller in the network as a naieve attempt to track a skeevy supplier, we're not going to get what we want due to the comingling problem.
>Big Table.
Instead, you have to think of Amazon as a big frickin' table onto which everyone throws their stuff. Amazon is basically the de facto merchant in all cases where fulfillment by Amazon is used. Since they bin by item, and not item/source, you get an assimilation going on.
>Borg: Essentially, Amazon is this. They absorb all the uniqueness of all of their suppliers, and essentially dissolve/absolve any particular supplier of singular skeevyness since all the skeevy gets laundered through FBA. Even if you have mostly upstanding sellers, the smaller populations of skeevy sellers benefit, because their fulfillment when picked have a high probability of being good, while the upstanding vendors are guaranteed to eventually eat negative reputation from skeevy merch being used to fulfill their orders.
>Merchant malfeasance analysis is simple: It actually is. You just separate out each source's inventory and track fulfillment from that inventory. Easy-peezy from a data point of view, but incompatible with real world physical constraints. The physics of the matter would be way too infeasible to implement, since there would need to X^n physical buckets where X is the number of items, and n is the number of suppliers of that item. If you were to track every type of item in clearly separated sub inventories keyed by source. That just wouldn't be physically or fiscally possible, because now Amazon needs pickers not just for stuff, but for supplier's of stuff. Suddenly, Amazon is open to potential complaints on relative picker staffing between suppliers, even if you somehow managed to handwave away the physical space requirements.
>The other view is Bullshit. The other view being that the Amazon marketplace backed by FBA allows for any type of reputation based curation. While the marketing team pounds that drum, it won't work in a world with limited physical space, as explained above.
Did I get it right?