In the example you cite, I agree - if someone just aggregate links generally, and had no intention of pushing people towards verified child porn, there was no intention there. Those link shouldn't be penalized.

On the other hand, if someone did verify the illegal content, and posts links with the clear, sole intention of driving others towards the illegal activity - then what?

I don't think you can decouple the link entirely from intention - links are sometimes expressive, as this article points out.

Instead of just giving ultimate, endless rights to link to anything for any reason, we say: base case, free speech, link to anything. But if someone can prove your intentions were illegal (no easy task), you're not necessarily protected.

Intention is a tricky gray area, but this would be in sync with other free speech protections - e.g. someone can press charges for libel on things you publish, but the burden of proof is on them to show the statement was false, harmful, and was made with malicious intent.