employment potential and learning are generally problems if you are young. if you are old, the time investment to learn a new language is generally not self beneficial as your time of employability starts to dwindle.

Linux ultimately will have to run into the situation of if the people want the newer language to become the mainstream, they need to be more proactive at the development of the kernel itself instead of relying on yhe older generation, who does ot the way they only know how, as relearning and rewriting everything ultimately to them, a waste of time at their point in life.

think like proton was for gaming. you dont(and will not) convince all devs to make linux compatible games using a vulkan branch. the solution in that front was to create a translation layer to offload most of that work off because its nonsensical to expect every dev to learn vulkan. this would be applied moreso to the linux kernel, so the only realistic option (imo) is that the ones who are working in rust need to make the rust based kernel and hope that it takes off in a few years to actually gain traction.