"Do A-Listers have a responsibility to link to Z-Listers?" I think not. Even if you've got a huge amount readers, it's your blog, not the blogosphere's blog.
Hugh's exactly right. He has every right to totally ignore any blogger that's not an A-Lister.
But my question is, 'Why in the world would you want to do that?'
When you start deciding which blogger's content is or is not worthy of your attention, based on something as arbitrary as their link count, you aren't hurting them, you're hurting yourself.
Which goes back to my original question: "Why in the world would you want to do that?"
The Viral Garden, Marketing