I use CGI.pm all the time, but I only use a very minor portion of the module (...) So why should I pull in the whole of CGI.pm, especially when web programming should be as fast as possible?
I use Perl all the time but I only use a very minor portion of the language... you get the idea ;--)
Basically the extra functionality comes for free. Have you looked at the code of CGI.pm? Unless you use a method it is never loaded. It uses tons of clever tricks, its own version of Exporter (saving you 300 lines), and under 700 lines of "real" code, the rest being loaded on demand.
Are there any benchmarks of CGI::Simple against CGI?