[Jim Jones]

That's all well and good, and many will agree with you. However, it seems to be important to the OP. So, let's deal with his question.

That said, I don't think sharpness is the only criterium either, but I'm always turned off by images that are not as sharp as they could be when they could be improved by sharpness. I'm well aware, unsharpness can be a creative tool (many good examples in the APUG library of that), but that shouldn't become an excuse for sloppy craftsmanship.

Very true. Even when unsharpness is necessary because of technical limitations, it need not be unpleasant. As I understand, Edward Weston had an iris modified for adequate DOF in his macrophotography. The contact prints were not be perfectly sharp. However, the subjects lacked the kind of detail that demanded critical sharpness. Optical limitation is just one of many factors we should always consider.