There are some things worth worrying about, but I don't think this is one
of them. The kernel can be cross-compiled, so its build requirements are
really not that important. Nobody sane ever compiles Linux on an embedded
system (by definition if it's embedded it's too small to do that sort of
thing), and 99.999% of non-embedded Linux systems have Perl on them.
A Perl installation requires about 30Mb. There's no way you could sensibly
compile a modern Linux kernel on a system with that little RAM, so what
you're saying is we should optimize the kernel build process for systems
that have less disk space than we need memory to complete the compilation?
This isn't so much premature optimization as pointless optimization.
(And no, I don't much like Perl: I much prefer Python and C. But still,
this is a waste of human effort.)