Having been doing sysadmin duties for more years than I care to remember and having gone through the gradual process of manual configuration -> shell scripts ->

Having been doing sysadmin duties for more years than I care to remember and having gone through the gradual process of manual configuration -> shell scripts -> cfengine -> puppet, I'd say despite problems in tools like puppet/salt/etc they are way, way more reliable and sysadmin friendly than shell scripts. For just one example, I've recently begun deploying CentOS 7 boxes whereas previously we mostly used 6 (and some 5). Largely the existing puppet modules kept on working despite major OS changes (hello systemd!). If I'd been maintaining a set of bash (or as used to be, csh) scripts I'd hate to imagine the amount of spaghetti I'd have to have mashed up. We've also got almost every Linux distribution out there you can think of, versions going back a decade or more, Solaris boxes, BSD's and not long got rid of our last AIX box (and I'm going to ignore the last couple of OpenVMS machines). Handling it with hand-rolled scripts was really not fun compared to puppet.