In photography, like all art forms, there are going to be dogmatic proclamations about what ART is and what a PHOTOGRAPH is or isn't.
I am not going to make any of those proclamations. Nor am I interested in rekindling some "digital/analog" debate (however, I might make judgements about print quality and what is BETTER—within certain parameters and end goals).
Recently, a photographer friend said, "If all you want is to 'capture' what you are photographing, then digital is fine. If you are interested in the absolute finest object you can make, then contact printing on silver chloride paper is the way to go." That same photographer often quotes e.e. Cummings in saying "an artist, who's every agony is to grow" ...
I believe that an artist should also know that sometimes the tools and ideas they chain themselves to are the things that actually keep them from growing.
And just like a master artist might work in oils or monumental sculpture it doesn't mean they stop sketching or working with clay in their hands. Photographing with an iphone or cheap digital camera can be just as informative in learning to see new things and make new connections. And just like the painter's sketches aren't usually finished masterpieces, neither are the photographers' Instagrams. They can, however, go to build the visual vocabulary when the time presents itself to make the finished work.
You can follow me on Instagram here: http://instagram.com/polasaurus_rex
I use it to make visual notes and snapshots, and there will the occasional long arm, picture of the dog, and broken down Land Rover. Seeing photographically every day is as important as other physical exercising. It keeps the muscles strong and active and makes it easier for when you do need make the next great picture. Or run from the bear...