You are talking about creating a system to make scam harder.

Don't forget that bitcoin is not the only coin that uses block chain, Altcoins also used block-chain.
I am not in support of fraud or scam, but come to think about it, if bitcoin introduces traceable transaction into their block chain, will all coins do ??

Let's be realistic, Most transactions done on the dark web are more massive than the legit transfers, Dark web and dr*g activities produce more money that brought most crypto to their main level today.