Wasn't it Ansel Adams who said 'There's nothing worse than a sharp photo of a fuzzy concept'.
It is clear that Adams was stressing the importance of subject, but the statement is saying nothing about the importance of technical proficiency.
At school I hear it all this all the time, about how 'story is more important' than technical. How you can shoot an entire movie using a shaky hi-8 camera in natural light and if the story were good enough, then it doesn't matter.
So frequently in film school we get wrapped up in this myth that if a story is good enough, we can just bypass all the craft - that craft is this sort of unnecessary technical inconvenience that our delicate "right brain" shouldn't need be subjected to. It does not help that in order to offset dreams of using $100,000 cameras to improve freshman's mediocrity, professors often rely on the "it's not the equiptment it's how you use it" line, which is certainly true, but likewise is extended to "it doesn't matter if you lack technical skills..."
As a technical artist, this pill is hard for me to swallow. So much of what I'm doing in school is tremendously technical, yet likewise aesthetically interesting. I can't just will this stuff into existence by virtue of my creativity.
The challenge with art is that it *is* technical, as well as creative. I will never be a great illustrator, not because I lack ideas - but because I do not have the manual dexterity that it requires. If you cannot figure out how to use a camera, you'll never be a great photographer, no matter how "creative" you are. There is no "single important aspect". You wouldn't say "it doesn't matter how bad your grammar is, so long as the story is good". Art is hard.
If the lack of sharpness (or whatever technical quality) distracts from the subject, it doesn't work. If the lack of softness distracts from the subject, it doesn't work. But no matter if the subject is better shot sharp or sharp you still need to know *how* to choose the right lens, the right focal length, the right aperture and the right focal distance. Otherwise photography isn't art, it's the occasional happy accidents.