Superuser's one of the 'original' StackExchange sites, AKA the trilogy - we predate the foo.stackexchange.com sites, which I believe started with SE 2.0
So yeah, we're older and as such have a cool domain name.
Links across the two sites may confuse new users. This is why the link is not there at the moment and why I'm marking your bug as status-bydesign.
Creating a new set of privilege pages for meta sites is doable, but it's a network-wide request which needs to be discussed on meta-so. I encourage you to discuss it there.