> PHP typically required a web-server, system administration which is old fashioned

IMHO deploying PHP to production is easier than Ruby/Python. You need a web-server but once it's configured (not a rocket science) you just copy all .php files. For ruby you also want to have a web-server (e. g. nginx) unless the load is negligible. If you want to deploy a project with all dependencies you probably need something like rvm but some gems would be easier to install form OS packages (like pg or other wrappers around C/C++ libraries installed from OS packages too). And then for ruby you need an additional daemon (HTTP) which will be restarted on updates (and auto-restarted if it will crash).