There's nothing inherent to these vendors (as people) and/or
(most of) their products that would mean that they shouldn't be allowed on Amazon, no.
The problem is instead with the shell game these vendors are playing — creating thousands of temporary brands, pumping them or "brushing" them with fake reviews, and then discarding those brands at a moment's notice when things go sour for them, only to replace them with another brand selling the same shitty products the next day, with the same people behind it.
Amazon's seller reputation system was designed to function under an assumption of "one persistent brand per group of people who work to sell a thing." But people noticed that Amazon uses "one legal company with a trademark" as a proxy for "one group of people"; and so have created thousands of distinct "legal companies with trademarks" with the same group of people behind them. Which Amazon's reputation system has no way of coping with.
If Amazon could deduplicate brands — i.e. require that the same group-of-people sticks to selling stuff under the same company/brand — then there'd be no problem, because then their reputation system would work: if the stuff was crap, the company/brand would get a bad reputation, and then nobody would buy their stuff any more.
The “hit and run” aspect, coupled with fake reviews are indeed problematic when they occur. It’s also baked into Amazon’s model: their whole goal was to make it more accessible to small and upcoming entities to go sell globally.
The only info is about the last 12 months, and we don’t get much clues about the business behind it, even as it has a full store page in Amazon. And of course Amazon wouldn’t want you to get too involved in a any specific shop, as it would strongly lower their leverage as a marketplace (shops stop being replaceable)
The problem is instead with the shell game these vendors are playing — creating thousands of temporary brands, pumping them or "brushing" them with fake reviews, and then discarding those brands at a moment's notice when things go sour for them, only to replace them with another brand selling the same shitty products the next day, with the same people behind it.
Amazon's seller reputation system was designed to function under an assumption of "one persistent brand per group of people who work to sell a thing." But people noticed that Amazon uses "one legal company with a trademark" as a proxy for "one group of people"; and so have created thousands of distinct "legal companies with trademarks" with the same group of people behind them. Which Amazon's reputation system has no way of coping with.
If Amazon could deduplicate brands — i.e. require that the same group-of-people sticks to selling stuff under the same company/brand — then there'd be no problem, because then their reputation system would work: if the stuff was crap, the company/brand would get a bad reputation, and then nobody would buy their stuff any more.