I take it you don't work on many disparate unix systems on a daily basis :) I find most of the time I'm lucky if there's even bash installed on the remote system, it's usually ksh. tmux? way too new. Python? Nope. Perl is the only scripting language I'd wage my balls on beyond awk if I hope to reuse the script again.

Sad, but I find this is generally the case in extremely large enterprises where there is a mix of AIX, HPUX, Linux and Solaris being used due to years of weird procurement decisions. Sigh.