A lot of people still have am/FM gear, and they're so invested into their primary communications which is so reliable they don't think about secondary communications. I have, which is why I'm a ham operator.

Most people at least have FM in their car, the broadcast range is in the lower VHF airspace, not much higher than HF. Most of the HF and LF bands are so tightly allocated that there's no room to just Willy nilly add another frequency for emergency use for civvies... which would require everyone to buy new radios, which they won't. Meanwhile, there's still shortwave, which people also don't buy that's already there and lower on the frequency range than broadcast FM... people need to be saved from themselves. Allocating something new and building a bunch of new infrastructure for it is idiotic. The structure is already there with broadcast FM, we just need to save people from themselves and ensure that they have access to it.

I'd be in favour of there being a dedicated broadcast FM frequency for emergencies only. It would become trivial to have a radio station change frequencies to the emergency broadcast frequency when something happens. We could even make the frequency digital instead of FM, and have it encode information by text, and turn it into a recieve-only text-based emergency channel... but making it a whole new band and new radio type on a different frequency that's not already set up for such a thing is insane to me. So much infrastructure cost for something we literally already have.

Any government that green lights such a program has lost the plot. Use what works.