let the buyer beware.
sounds like a good theory, but it depends on the integrity of the marketplace.
and the marketplace is about making a buck.
will folks make a buck regardless of the integrity of the market? of course many will. how many people care about the abstract? not so many.
reputation partly resolves the issue - but bad reputation is accrued at someone's expense.
why should those people pay the price of this valuable discovery on behalf of everyone?
meanwhile, the bad actor may have made a fortune and moved on to a new market.
if caveat emptor applies, rogues profit and honest buyers suffer.
so ... caveat emptor implies the erosion of markets through the gradual loss of integrity.
what to do?
markets rely on regulation by an agency which is not beholden to the market's sell side actors.