I think it's a little worse than that. There are a
couple of warnings in Perl5 that frequently get
triggered without any real problem in the code. I'm
thinking most especially of the one when you
interpolate a value that might or might not be
defined, and it happens not to be. I
have never yet once seen a situation where that
warning was useful, but many, many times I have
found myself introducing excessive verbosity and
needless complexity to the code in order to suppress
it.
I've also occasionally been annoyed by other
warnings when I knew very well about the thing
they were warning about but for one reason or
another did not consider it a problem, and I
wished I could just make the warning shut up.
I heard a rumor that Perl6 is going to give us the
ability to shut off individual warnings, without
losing the ability to see other warnings. I look
forward to that.
Nevertheless, the clown described in the original
post is making future trouble for himself and/or
someone else.