Putting on my tinfoil hat, I think there’s also an argument to be made that the NSA might want to slow down adoption of post-quantum algorithms, which their stance against hybrids definitely accomplishes. If there’s a single organization that could be 10-20 years ahead of where people think they are on something like a useful quantum computer, it’s the NSA (powered by the US’s absurd defense budget). If they can slow down the adoption of post-quantum algorithms, they can maintain their potential head start for longer and be able to break current cryptosystems and extract actually valuable information.

Outside of the NSA (and its affiliates), most of the cryptographic community seems to have come together in support of hybrids, which would greatly accelerate the adoption of some level of post-quantum defense. With even the most “liberal” cryptographers thinking that more careful cryptanalysis of post-quantum algorithms is needed before widespread adoption as the sole line of cryptographic defense, if the NSA manages to convince sufficient people that hybrids aren’t viable enough for production (and thus stick with classical algorithms) they may be able to maintain the ability to break sensitive communications for longer when and if their quantum computer efforts have a breakthrough.