The reason why 'pretty' and 'visually appealing' alone are not enough is that they do nothing. People might give the image a glance and think 'yeah that's pretty alright' and never think or take a look at it again. Nothing altogether has been accomplished.
I might be wrong with this, of course. This might just be a stage in my thought process, and later I might come to the conclusion that if something is not pretty enough, it's meaningless, but when something is absolutely beautiful, the human eye and the brain are by some evolutionary reason simply drawn to look at the image and absorb the beauty into their souls and never be sad again...
What would be a better approach, then? To have the story ready before the pictures? To have a noble cause and to look for a story and a way to put it in a picture? To see or experience something intriguing, and to study it and to capture the feeling into pictures?
There might not be a right answer to this. (Too obvious, huh?) For pedagogical reasons I have already been put outside of my comfort zone to use very different approaches for my university assignments: technical, observational, careful studying. I would assume that I will have to try many more approaches, and hopefully learn to use the one that I need each time.
Whatever the approach, some of them will require planning. However, all of them have to have an aim*. The success of an image can only be compared to its aim. Does this fashion advertisement increase the number of sales? Does this family portrait reflect life at that moment? How well does this portrait describe the subject? The aim is the way we judge the result, and the approach should support the aim. (And if the aim isn't very high, that might be reflected in the approach, as in the first approach discussed.)
*This, of course, applies not only to photography but to all creative processes, and is not limited to them only
The two images in this post are from the same photo shoot which I conducted in my shower. I had a certain aim, which was to use slow shutter speed in a meaningful way. From that technical aim I proceeded to a semantic and a conceptual aim. Because of the lack of technical understanding I completely failed to create that image. After deciding that it was no use to try to reach that particular aim in the current situation, I changed my aim and tried a couple of other things just to play and explore, as I already had my camera on a borrowed tripod and my black sheet was already wet.
Maybe this is a demonstration of how I succeeded in improvising in a situation that didn't seem promising to what I had planned. Eventually I did not reach that, but I got something else.
I feel like I just wrote all of that above to state the obvious. However, I am writing this blog for myself, and if this is what I need, this is what it shall be.