I would say it’s more of a desperate attempt to continue the current paradigm of online advertising which deems indispensable the kind of data about conversion rates to which the industry has become accustomed, despite the recognition that their current means of collecting it must come to an end.

But either way, it’s incompatible with the principles of free software. Users are not meant to put up with features that are there for the sole benefit of someone else; someone they might normally consider an adversary. The only incentive we’re given to participate in this scheme is one that resembles blackmail. Except it isn’t even advertisers saying “do this, or we’ll spy on you like usual” — it’s Mozilla saying “do this, and maybe we can persuade a few of them not to spy on you as much, and to give us a cut.”

They are selling behavioural data about their users to advertisers. People are not going to be happy with that no matter how they try to spin it.