This interview does a good job explaining the appeal of this camera to pros...
I have found the experience of going to the movies less special/distinctive since digital projection became so ubiquitous at theaters. It is not necessarily worse and does have many advantages, but there is definitely a cinematic feel that I feel has been lost with the switch (a feel that I loved getting to hark back to w the hateful eight). Now going to the theatre feels more like watching a movie @ home.
That is why I would totally be on board for this. With todays totally reasonably priced projectors/5.1 systems you could put together an awesome home theater for less than $1000 if you have the space. I have an old budget HT system I put together in 2011 that always amazes me to this day with how cinematic it feels.
The $50 sounds high at first, but between concessions, babysitters transportation whatever you can recoup it pretty quickly especially if you have 4+ people. This might not be for everyone, but sounds like an awesome niche product.
Phillip Bloom addresses this exact question really well in his review of the a7s around the 30 min mark.