We don't really need a documentary. Everybody's getting a documentary these days so it's kinda refreshing not to have one.
3 documentaries come to mind. 1 about Cullen, like a love letter from the fans, 2 a doc about toy collecting in general, how things have changed and its normal for adults now to collect toys or embrace their nostalgic desires and 3, a cazy insane TF doc where we all act like fucktards. Interview the wackos only here. Chasing people in stores, biting them and ripping their TFs from their arms. Scalper beatdowns, stuff like that.
If there was a crazy documentary about TF fans it would have to include this scene Aernaroth suggested:
There's just not much that is interesting about a bunch of grown men (and some women) that collect Transformers. Now, a case could be made for a documentary about adult toy collectors in general but it would basically be called "Neckbeard: The Movie". Or Reddit. If they all used sig & avatar pics of teenage anime girl panty shots I'd agree. It's stuff like this that makes me extremely reluctant to ever admit that this is a hobby of mine. Just like when I stopped wearing a fedora, there are just certain things I really don't want to be associated with.
I think the main reason Bronies got a documentary is because it's grown men who like a girl show, vs Transfans who are typically grown men who continued (or got back into) a boys show from their childhood. That is the key factor that makes you go "Hmm..." I mean, look at Star Wars collecting - there's only been a handful of documentaries on that and it's been around a little bit longer.