Not sure exactly what you're asking.

We can evaluate the Linux kernel developers' priorities by benchmarking[1] and assuming they aren't stupid, because if they are stupid, then their opinion doesn't matter, and if they're not and they're not making things faster, then it's because they have other priorities.

That being said, there are a few[2] notable[3] moves away from linked lists that were ostensibly for performance reasons.

[1]: Even crap benchmarks: http://www.phoronix.com/scan.php?page=article&item=linux-44-...

[2]: https://lkml.org/lkml/2016/8/1/164

[3]: https://lkml.org/lkml/2008/4/1/458

You provided a reason for why the kernel does a certain thing (easier to code; performance in those places doesn't matter). I was asking if this was your understanding based on inference (your understanding of the performance trade offs in general combined with the fact things are done a certain way) or from fact (claims made directly by kernel developers, or experiments).