To me personally, however, this is a very bad smell. They have shown that they will push unrelated code as a Shield Study. This faux pas was signed off by a Firefox Product Manager, Data Steward, Legal, QA, Release Management, AMO review and a member of the core Shield Team [1]. If none of these members realized it was a bad idea, I have lost all faith in their product development. If it wasn't signed off by those members, there is a major red flag about who has the ability to add these types of things and/or their processes.
Either marketing has too much say, they have poor processes, or they are totally out of touch with their user base. These all raise red flags for me. I can't feel confident knowing that there is no spyware in my browser.
Mike Conley a Mozilla dev commented on the bug ticket, "I am also curious about this. I have been asking around, and have not yet found a single Firefox peer that was involved with this in either implementation or review."[2] Everything about this was handled incredibly poorly. I will wait for the postmortem, but currently I don't have a lot of faith in Mozilla or their processes.
[1]https://wiki.mozilla.org/Firefox/Shield/Shield_Studies [2]https://bugzilla.mozilla.org/show_bug.cgi?id=1424977