Since most people who will be subject to ransomware have no way of knowing the mechanics of the encryption (or wouldn't be able to access it anyway)
Well... IF the tool becomes widely-enough known, that when a victim goes looking for some tech to help them, then it could be very useful. As opposed to real public/private key encryption where no one could legitimately help them.
I doubt this will happen; I doubt the tool will be utilized; but it's at least been made possible now. (And of course, new versions of the malware will keep popping up...)