"and there's this bit over here I got that I use for soandso and it seems to work well."

That is an argument agianst all modules good and bad, big and small, core and non-core. Realy though it doesn't hold water. In any langauge you use peices written by other people, maybe its a sort algorythm, a linked list library, or some other such thing. In all cases you have to combine a bit of trust, a bit of research, and a lot of faith in the community that these thing work. This is part of the reason agianst lots of template systems. Right now it is easy to say (and remember) that TT is good for one thing and HTML::Template is good for others and maybe sometimes module Z. It is also easier to research them because there arn't tons. If however we let many many bad template modules get onto CPAN then we have a whole forest of bad answers with a few hidden flowers. So your issue with trusting code is part of the very heart of not wanting tons of Template wheels rolling around.