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?
For a while I thought along these same lines. But RBF is effective, and the network works securely as designed, because nobody is transacting bitcoins using wallet addresses with private keys in the low bit range. Puzzle 66's private key is at 0.00000000000000000000000000000000000000000000000000000000040025374665586730511
0971121712095050954258 x 100 percent of the keyspace.
In other words, if the keyspace was the distance between earth and the sun (147m km), 66's private key is not even a nanometer off the ground.
My math is probably off by a bit but just trying to help visualize the issue.
