How about this:

I opted into FF telemetry and "studies" with the understanding that some extra data would be collected and experimental features or specialized debugging tools might get pushed to my browser (like the last "study" I saw for collecting JS errors).

This addon is none of those things. It is an advertisement. Call it an "alternate reality game" if you like, but it's an advertisement for a television show. It has nothing to do with making FireFox a better browser.

Using the Shield Studies program to deploy extensions and advertisements that have nothing to do with the original stated purpose is an abuse of the tool and a breach of trust.

That's all aside from the fact that there's been numerous reports of people receiving the addon who never opted in to Shield Studies in the first place.

Raising awareness about security and privacy relevant issues from a TV show seems to me like it (indirectly) makes Firefox a better browser. An AR game does nothing to improve the browser by itself, but think of the big picture. Cultural awareness is a big part of it.

If you want to take an ideological perspective, the big picture of this is that the browser maker is willing to push advertising software to people who didn't ask for it, over a channel that wasn't built for it, to further a political agenda.

Even if it's ostensibly about ideals I might agree with, this was a very poor decision and a breach of trust.