Apple did put in the effort to cooperate when they added support to boot other OSes. Apple hasn’t prevented anyone from running Linux, they simply haven’t written Linux drivers for their hardware or provided a manual to do so.
Most of the effort in Asahi Linux is going to be writing drivers for hardware that hasn’t had Linux drivers written for it. It makes sense that a Linux driver doesn’t exist, because this hardware is new and no one has tried to run Linux on it before.