Data::Dumper is a case in point. It's a dumper for Perl variables, not data more generally. Can it be used as a drop-in replacement for PostgreSQL's pg_dump command? Not without loading that data into Perl variables first. Calling it "Variable::Dumper" would have been more descriptive.

Data::Dumper isn't an absolutely awful name for what it does, but there are better names that could have been chosen. Virtually all modules deal with data in some way; that doesn't mean that virtually all modules should sit in the Data:: namespace.