This came up in another thread, got off on the wrong foot and then got back on track, off-topic, so I thought I would pull it out and give it its own space.
What drives you? Why do you do photography at all, and why do you do the type of photography you do?
And of interest in this themed forum: what drives equipment purchases?
1) My primary motivation is the space I am in when I make photographs. I love the feeling, the thought process, the routine, and everything about it. This part can be done with any decent camera, like my M6.
2) A close second is seeing the results and working with them. I love getting a great shot, and work towards increasing the frequency. On a sidenote, I think maybe the frequency of shots I really like doesn't increase, but my standards just creep up to match. Ansel Adams once said that he estimated that he got 12 good shots a year. I know exactly what he meant (although his 12 good shots cannot be compared with my 12 good shots).
3) My equipment upgrades are motivated by the desire for artifact-free images, as well as the ability to enlarge more without losing the image the digital soup that results from enlarging too much. With artifacts, I mean primarily things like coma, CA and so on, but also better boke, more sharpness, etc. Another reason is to enable more types of shots, like long lenses to get closer, etc.