I might be wrong, of course no one has any figure about module usage, but I believe the people who write Perl modules "the XML way", like Matt, Robin Berjon, Ilya Sterin etc... are in a way off-target. ... The modules they write are not what the Perl community wants.
I have to disagree with you there. Kobesearch.cpan.org keeps some stats, and it shows that beyond the base XML::Parser, XML::DOM is the most popular, followed by libxml-perl (containing the PerlSAX1 code). Granted XML::SAX or other modules like it aren't on the map yet, but the above two modules show that Perl XML users do want standards based tools.
But I do love XML::Simple - it hits the 80/20 sweet spot most of the time. However I'm much happier now I can use it via SAX not just with XML::Parser, because sometimes (e.g. with mod_perl, or when you can't compile XS), XML::Parser isn't the right tool for the job.
Maybe you've missed the point about XML::SAX::PurePerl though. Nobody should be using XML::SAX::PurePerl directly (except perhaps SAX module writers test suites). It's simply there as a backup - to try and be a lowest common denominator. That's all. Plus it stops people complaining about there being no pure perl XML parsers ;-)