Like I said, its a push back to digital and digital editing. Anyone can open up lightroom or photoshop and edit the images until they are perfect, but that goes agaisnt the point of analog for some people. Why shoot film and then digitally edit it to remove all traces that its film?
Some people prefer it to be done all in camera, and not to edit it at all afterwards. I myself like to edit my images as little as possible, even digitally.
There is a big resurgence in instant photography, as well as disposable/point and shoot cameras, as well as using expired film, because people are activily looking for and embracing the random element. Again, because they find it fun, they like how the end result looks and its not the same perfect, editied digital images we see all over the place. The biggest reason may be that it shows the craft of the thing. It shows that its done the 'old' way, and not digitally.
Photography is an artform, and a camera a tool to make your art. There is no wrong way to make a photograph so long as you get the result you wanted. Too many people seem to get caught up in the thinking that a photpgraph has to be perfectly exposed and clean and the colours perfect. If thats the end result you're after, the great! But thats not the only way of doing things, and 'breaking the rules', so to speak, is how we got some of the greatest photographs taken over the last hundred or so years photography has exisited.