Python grew out of a myriad of applications that built on hard to replicate components, while Ruby relied only on web development which is remarkably subject to fashion. Python is very simple making it easy to learn. Thus, it became more and more popular for fields where programming is not the main task, like science. It is also very easy to extend with C. So, these fields could bolt on time-tested scientific code in…
Chef, Puppet, Vagrant, Logstash, etc are not web development.
Ruby dominated (dominates?) DevOps tooling.