Granted using premade CMS systems (PHP Nuke, e107, portal mods for forums, mambo etc) are a major time saver, and most when modded some can work very well for quite a few applications, but there is still always a limit to how far it can go compared to something you made yourself.
for example about two years ago for some odd ball reason, i wanted to create a whole automated gaming league, php/mysql backed, CSS driven, complete with session and member management, and i hadnt a clue at the time on how to make any of those things. attempted to make one from scratch, but when you are starting out it can be pretty intimidating. so went with a forum system i liked, slapped a portal mod, and slowly began learning how everything went together and how it all interconnected.
this is what i started with
http://astralfoundry.com
this is what i ended with on that venture
http://mercarena.com
now 2 years later and many more sites and mad projects, after messing with a premade CMS and forum system, i have created my own (still rough but it works for a first attempt) that powers my teams new site
(demo here,
http://universalwebsiteservices.com/robotics ) (please PM comments)
honestly, now from what i have learned from modding and redesigning most premade CMSs, other then just using them for a genaric site, they are worthless but they do make a great starting point for someone to learn how to make their own. IMHO i think, in general, that some rely too much on things like php-nuke(never cared for php-nuke at all, i think the whole phpbb backed system are next to worthless, extremely simple systems, horrible backends, but good article and download systems) when one can make their own, but everyones got to start somewhere.
FIRST is all about learning new things, if it teaches someone something and allows them at a later date to apply it for their own use, dont see why it shouldnt be used.