1. The use of old cameras would have to be my top reason. I currently have two Canon A-1 cameras which date back to the late 70s. Initially I started with a Canon EOS 10 from the early 90s. Both are two very different cameras. The A-1 is obviously much older and did require a bit more getting use to (but still easy enough to learn). There is also the Canon AE-1, which is a popular camera for getting started with film. And of course the EOS 10 which is quite similar to modern Digital SLRs, it's compatible with current EOS Canon compatible lenses. The older cameras produce a certain look, mainly because the age of lenses with a bit of growth, a bit of flaring (no or little UV coating), which I believe adds so much character to the final photographs. Loading the film is quite rewarding too, as you never know what might turn out. This is a combination of both film and camera.
2. The journey of shooting with film. The choice of film, speed, colour or black & white, all have their own unique flavours and results. From loading the film, to framing, coming up with a vision of what you want to shoot, or travel, or try a different approach.
3. Experimenting. I love seeing what kind of result I get with different techniques. I currently write an infrequent blog about what I'm up to and about my technique and approach. Coming up with a location, a process, different lenses for different results.
4. It has slowed me down so much. Shooting film requires greater patience in part due to the cost. I certainly don't let that stop me from shooting, though. After I come up with an idea, or always consider the framing before shooting. I am a bit obsessed with light and lines, so that is a big part of what I photograph. I try for different angles and different approaches to everyday scenes.
5. Good conversation starter. People are always curious about why I shoot film and the age of my camera. I hope this is enough to keep film alive as I believe between film and digital, it's not necessarily better just different.