The only "scam" was self-escrowing and collecting fees for it.
He was caught using his DT and alts to farm trust among his own accounts. He was also caught using multiple alt accounts to neg trust single users. (Panthers52, ACCTseller) There is no question that he is untrustworthy.
More than anything, though, Quickseller's bullying attitude and sociopathic approach to morality are the red flags.... I believe he was orchestrating a long con, and was simply outed before ever pulling it off.
Personally, unless he scammed someone, it shouldn't be that much of a big deal. Just be made clear to everyone who's accounts are who's so people know who they are dealing with.
Though it is pretty fishy behavior and warrant getting drop of the DT list for sure.
I just don't like to debate morality, especially on the internet, but yes i understand why people would be wary of a long con.