SEC only wants to regulate decentralized blockchains, because as Goldman admitted, the technology, which requires no trusted intermediaries, makes banks and other entities which offer financial services and financial institutions, including the SEC, which gets power from regulating them, obsolete. There is a clear conflict of interest, between the SEC and the technologists.
A credit card machine costs at least 700$ in fees, average, plus percentage of the transaction; a blockchain address costs small flat fees, and nothing up front.
Never imagine the SEC wants to actually reduce the number of scams; it wants to protect its vested interests, scare off the silicon valley programmers from eating the wall street pie.