awk is also a much smaller language than perl, so it's generally less effort to teach, learn, and read.
Asking a new hire to "learn awk" vs "learn perl" have two very different time investments attached to them.
Tasking someone with "learning a subset of perl" begets the question "what subset?", and a very exhausting conversation with someone(s) routinely asking "so?" follows. After spending a large amount of time re-litigating which subsets of perl features we want that awk already supplies.