I don't want a lot of this stuff in the core simply because I'd like the core to be as minimilistic as possible (for one thing, it would encourage new programmers to use modules). It's too late for Perl5, but I can dream, can't I?
Well, there's always Python, where you can't do a lot without including at least one module. And then there's C where you can't even do I/O without the help of a library. I love a language where I don't have to remember in which module which function was defined so I can use.
As for your reason, "to encourage new programmers to use modules", most people are interested in getting more people to program Perl by making it easier for new programmers. It seems you have a different view.