Allowing encryption wouldn't make ham radio any more an option than their GMRS usage. To the extent that someone in far off nowhere might make some rule violat

Allowing encryption wouldn't make ham radio any more an option than their GMRS usage. To the extent that someone in far off nowhere might make some rule violating usage (e.g. using it commercially) it's moot: they already can. They're at risk of getting caught and getting a forfeiture order and fine, but they are regardless of if they use encryption or not. Practically in those locations the likelihood is that they won't interfere with anyone at all in any case. In which case it's irrelevant. What's vastly worse than a bit of misuse is losing the bands entirely. We've essentially lost 9cm (half already, the rest when the FCC finishes selling off the half). But for a few hundred KHz used for EMEers (whos numbers are only in the hundreds) the bands higher than 23cm are essentially unused, and 23cm has quite limited usage. There is tons of UHF+ non-commercial and experimental radio activity going on _outside_ of amateur radio however, innovative things with SDR and mesh networking to gives some examples-- but due to antiquated content restrictions its operating (usually unlawfully) on the ISM bands and struggling with interference from other activity there and with low power limits (even though much of the experimental usage is unlawful, it still stays usually stays low power since folk wisdom says that's what keeps the enforcement away). These applications are squarely within the purpose of amateur radio and to the extent that they used non-certified homebrew hardware and antennas the amateur service is the only place they could lawfully operate. But in practice the content restrictions have more force than the requirement for type-certification, and the ISM bands don't have hall monitors, so as a result the vast majority of interesting UHF+ radio experimentation is outside of the amateur service currently. This is a serious danger to the continuation of the amateur allocations. (at least up at those frequencies).