I think you need to be more careful with that argument. While I agree in principle that this sort of flaw is inevitable in the future, and puts a hard cap on the value of measures like secure boot (and I'd go even further and argue that it makes the costs of secure boot higher than the benefit), it's not correct that the signature process is inherently compromised. Public key encryption works, and it works very well. There have been a handful of goofs, and there will be more in the future. But the number of key regimes that attackers would want to compromise (consider even banal stuff like the signing keys for console games, which remain secure after many years) vastly (vastly!) outnumber the few exploits.