[richdougherty]

Why not just pay the publisher the (possibly low) value of their traffic, while also providing the publisher with the tools they need to improve their traffic quality? If the site never improves then it simply never makes any money.

[stevencorona]

The networks see low quality publishers as diluting the overall quality of their network. Since advertisers only care about traffic that converts, low-quality traffic hurts stats because it makes CTRs and CVRs drop even if the overall CPC/CPA is the same.

There are absolutely ways to educate publishers and advertisers, but the easiest solution for the network is to just nip it at the bud and drop low-quality traffic.