For me, the art of photography is about getting the most out of the equipment you have. If it was easy, everyone would be doing it and there wouldn't be any reason for professionals to exist and there certainly wouldn't be any profit in it. Of course, as a business, the likes of Canon, Nikon, Sony and the rest wouldn't worry about that, as they'd potentially sell more cameras. I'm not really convinced by the dynamic range argument either. Yes, there are situations where more dynamic range would be nice, however, the reality is, without processing, images tend to look flat, so would need more processing time. Also, I feel that most of the DR would be wasted anyway in terms of professional use. Currently, the main markets for selling images are as fine art prints (either as true fine art portraits/landscapes etc or as wedding/event prints) and the various forms of stock. Most professional printers and paper has less dynamic range than can be produced by DSLRs, so having more dynamic range would be pointless in my view. Likewise, most stock photographic licences are purchased for printing, either in a magazine/newspaper etc. or on a billboard, again, the DR is wasted. There are more images being licenced for web use, but again, viewing on most browsers gives limited DR.
The challenge for me is the ability to capture the dynamic range and the scene as a whole in such a way that I can capture it without endless hours in Photoshop (I simply don't have the time) in a way that no-one else can. If I'm shooting landscapes, then I'll use grad filters to compress the DR to a usable range, it doesn't always work, but for most scenes it gives me enough to work with. I think this gives a much better look and I feel that smooth tonal gradations and nice contrast are far more important than a large DR. Lenses then become equally important, if not more so. Larger sensors are usually better in this regard than smaller ones, hence why full frame sensors have a certain "look" and why landscapes shot with larger format sensors tend to look better. Often it is an indefinable quality that gives a certain "look" and it is certainly down to more than just DR. Others have mentioned that they prefer the look of Canon cameras to Nikon and it is the overall sensor design that achieves this. When it comes to Wildlife DR is often more of a problem than landscapes, particularly birds with significant areas of black and white, but sometimes CPLs can be handy and most wildlife photographers are looking for soft lighting anyway, where there is less DR required. In fact for me, good lighting is far more important than improved DR, unfortunately, camera manufacturers haven't yet found a way of getting nice soft lighting throughout the day.
For hobbyists who are probably more inclined to look at their images digitally, perhaps on a high DR monitor, then I can see where they might want more DR, but for most professionals or anyone who is trying to sell their work, then print is still the major medium, so more DR is less important, as they will use technique to achieve the results they want. Very few pros are interested in the detailed specifications of cameras, they just want to know if they can get the images they want, for most it is simply a tool and they will get the best toolkit for the job. The photographic toolkit is a combination of body, lenses, filters and other accessories. Similarly, while there are some uses for large format printing, the vast majority of prints are easily achievable with 22 MP. CPS class the 5D series as a professional camera, so that is obviously Canon's prime target market, it's just that the original 5D and the MkII were also popular amongst hobbyists and semi-pros.
Personally, if I have to push images or part images more than a stop or so, then I made an error and it is discarded. Often on a shoot, even if I know I can process it to get it looking good, I will still reshoot with the correct exposure, even if it is only half a stop out. I also know that I can usually work better with highlights than shadows on my 5D MKII, so I will expose slightly to the right to compensate, as long as I don't go too far. My style though, does rely on shadows, detail isn't always necessary in smaller areas and it can add to the feel of an image. Using the whole dynamic range is important to me and I will often make use of shadows, despite criticism, as it is an artistic statement for me. I feel that increasing the available DR too much would lessen the impact of many of my images. In short, how an image looks is more important than what the specs say. Art isn't a science and data doesn't tell the whole story. I'm always reminded of the saying "Lies, lies and statistics" and I often think that specification lists and camera tests fall into the same category as statistics.
