RBF is not poorly implemented, remember everything about Bitcoin transactions is intended for 256 bits range not 66 bits range, if this transaction was made in 256 bits range, then no matter whatever you try about RBF, you can't steal the coins...
I say that it is bad because it is not effective, I think that all nodes should be subject to a standard, what is the sense of RBF off/on, if you can use another node with the possibility of replacement? It is not 256 bits. It is a security issue, suppose you have a security system, where if it is violated or attacked and detected, the system could move its assets by automating a bot that sends the funds to another safe site using RBF, but this is not possible due due To their bad implementation, how many coins would not have been saved from the Hakers if this were a standard?