sub is_all_in_bold {
    my $title=shift;
    my ($title_content)=$title=~m!<title>(.*?)</title>!s;
    $title_content=~s!<b>.*?</b>!!sg;
    return !$title_content;
}

while (<DATA>) {
    print;
    chomp;
    print is_all_in_bold($_) ? "Its all in bold\n" : "Its not all in bold\n";
}
__END__
<title><b>Meta&hyphen;Ethics and The Problem of Creeping Minimalism</b></title>
<title>Meta&hyphen;Ethics and <b>The Problem of Creeping</b> <b>Minimalism</b></title>