This new opcode would ignore any SIGHASH flags on a signature and instead hash the current transaction without input references before checking that hash against the signature. The proposed implementation would allow for Decker-Russell-Osuntokun with an internal Taproot point to be a 2-of-2 and then have a script OP_1 OP_CHECKSIG_WITHOUT_INPUT. If special scripts are already supportable by Taproot, why aren't we concerned about Taproot abuse? In closing, the author is questioning the lack of concern regarding Taproot abuse if there is such concern over SIGHASH_NOINPUT abuse.