That's only because they are focusing on upstreaming all of their work into the kernel first. A handful of them spent a small amount of time building some device trees for M3 and it didn't take them long to get to the point M1's were at at the first release of Asahi.

I imagine once a lot of the cleanup and maintenance is done on what they have, they'll be in a better spot to accelerate support for other SoCs, and it probably won't be half a decade before the M6 or whatever is supported.

All said, Apple could just spend a tiny tiny amount of their warchest and just ship some goddamn drivers for Linux a la Boot Camp and save the Asahi team the time divining it from the tea leaves.

Unfortunately, Apple is not one to revisit their previous decisions very often. With the move to Apple Silicon, the capabilities of the bootloader were locked in (chain-of-trust, ability to load other OS and keep chain-of-trust on macOS) and that was it. Apple is telling you what they support; there's never any damning secret with them. You want to run Linux? Run it in a VM on macOS. That's what marketing has been saying since day one of the M1.

Them's the breaks.