I use it mainly out of habit more than anything else. I have a few random CGI scripts on my shared hosting for small personal utilities and it's just habit to start with #!/usr/bin/perl -wT even though I am the only person who will ever use them.
"Excuse me for butting in, but I'm interrupt-driven..."
Probably used it ages ago for forms that were open to the entire Internet .. the forms I've used more recently are internal, so I get by with placeholders for anything that goes into the database. Recently .. nope.