My point is that short of picking the search results randomly, any mechanism will have some rules (no matter how complicated) that affect how things get ranked.
So be open about the shortcomings in your algorithms instead of trying to show that the practice is bad, try telling people that your algorithm is not competent enough to know if the intentions are good or bad.
Hence your algorithm requires you to comply to the nofollow rule.
If they did fix their algorithm, no one would pay for link spam any more.