I hope people can understand the importance of having a fall back,
pure perl implementation of some of these modules. I do understand that
in many instances, these modules are much much slower, but it is better
than nothin'.
The problem is you can't easily have a pure Perl implementation in
every case. In particular, a module which implements a binding
to some C library, would have to re-implement the entire functionality
of that library in Perl... (think of Net::SSH::Perl as a (more
or less failed) attempt along these lines). Similarly, if you need to
make system calls into the OS.