I don't think this is fair. It's not like we have great privacy now, and Mozilla is in danger of giving it away; advertisers already fingerprint your browser and tie your traffic back to a real-world identity today. I don't think PPA would help them do that any better at all.

Mozilla's position is, instead of the arms race to hide/identify traffic, if the browser builds in a way to measure conversions that doesn't rely giving up your identity then advertisers have less need of getting at your identity through other means. (And they haven't said this, but I assume the next step is, if advertisers can measure conversions then it becomes easier to envision legal countermeasures in the form of regulation)