It is safer, since the template developer has no access to naked Perl. It also seems of no concern because the template developer is me or my office mate.
IMHO, it's not because the template developers have access to "naked Perl". Rather, it's to protect them from having to code in complex programming language. The term "separating content (data) from display (view)" is really for roles in development instead of persons. I'm mostly a team on my own (except when I'm in a Real Team) so I need to think as programmer when coding Perl, think as designer when preparing the template, for instance.
To the question and examples at the end of your node, it's very clear. In your "pure" Perl implementation, "you" are thinking twice over two things in one session. In the templating solution "you" are thinking once for each thing in one or two sessions.
Open source softwares? Share and enjoy. Make profit from them if you can. Yet, share and enjoy!