Because somehow AMD's board convinced themselves they could jump straight into Apple's ASP and margins per SoC without having even a fragment of Apple's brand perception and software ecosystem that they spent decades building upon.
I.e. AMD isn't pairing a full Halo IOD with e.g. a single CCD at a competitive price out of hubris and a failing market research team. Strix Halo isn't selling, but AMD is apparently willing to die on the "I'd rather not sell it at all if I can't have a >100% margin" hill.
And the fact that virtually no one picked up STX Halo for laptops means AMD apparently didn't even consult laptop makers to know what they'd like to see and how much they'd be willing to pay.
Hopefully,
@adroc_thurston will be wrong / plans will change again and Medusa Premium + Halo will have a perceived value that put them on laptop+handheld makers' roadmaps instead of driving them away like they're doing with Strix Halo.