I find it extremely frustrating because I do think that links can be manipulated. People buy links, people spend enormous amounts of time trying to "swap links", you have no control over the so called bad links.
As a site owner, I'd still like to be judged on my content and not who is or isn't linking to my site. I think it is too easy to abuse and it is too easy to be penalised (for dodgy links you didn't ask for).
I know they do pay attention, but I just don't like the idea.