But it is.
Perl and awk one liners are very common. Bash is used everywhere you have the (controversial) `sudo curl .. | bash -` install method.
Ansible, if I'm not mistaken, requires python3 installed on remote hosts.
If your environments are homogeneous enough, and you don't have a large matrix of operating systems, you should definitely use this advantage.
The troubles start when you have very heterogeneous environment, custom or hardened Linux distros and etc.
It might seem like this is not being utilised as much nowadays, but I suspect it's because the "classical" Linux sysadmin roles are rare and you don't hear about it as much.