in a capitalist society, small/rare usually means high-paying! don't make it your career but it pays to know these things when writing your high-level code.
Small/rare in the supply side is only high paying when the demand is not as small or as rare. It really depends on that relation. Based on the comments I'm seeing... sounds like everyone is talking more about the demand side than the supply side... which sounds either on the edge of oversupply or just plain oversupplied.
Otherwise, I agree with you. Those that understand low level issues tend to, in my experience, just plain understand computing better... even if they're working in the deeply abstracted high level code.
The demand is quite low. I think if you want a good low-level code implementation, you can easily find one on github. For example, you can easily find a good compression algorithm for your CPU budget or other application needs on github. So you can get away with mostly writing high level code and using these external libraries. Second, the demand for writing really optimized code is not as high as 10-20 years ago. Now, writing reasonably fast, readable code is OK and no one expects you to run gcc -S and count cycles unless you are working in some high frequency trading firm.
Otherwise, I agree with you. Those that understand low level issues tend to, in my experience, just plain understand computing better... even if they're working in the deeply abstracted high level code.