This is NOT a scam accusation and there are no rules broken (as far as I know) because there are no rules against multiple accounts but I just find it quite weird.
Since technically all of these accounts belong to a single user
[most likely], then the following rules have been broken:
13. Bumps, "updates" are limited to once per 24 hours per thread. Bumping multiple threads at the same time is allowed if it's not annoying. [2][e]
30. Similar marketplace items must be listed together.[2][e]
32. Posting multiple posts in a row (excluding bumps and reserved posts by the thread starter) is not allowed.
You're right but other than ATM being just spammers it's not worth the effort.

Frankly with all their threads I don't believe they sold a single item and there aren't any scam complaints against them (yet). All the fake "vouches" are way too entertaining. It would just take too much effort trying to explain them all in a moderator report!