When the sun is at its highest point in the sky the light is at its whitest and strongest. Contrast is very high, shadows are very dark, so dark in fact that film emulsions generally render them black - although with the naked eye it can still be possible to see some detail in the shadows. For this kind of lighting to be believably recreated it needs to be very strong and high contrast.
The strong light has the effect of bleaching out colours and these appear to be less saturated than at other times of the day. The strong contrast can make it difficult to create appealing images in this sort of light, however in situations where contrast is naturally lower it can work very well. Water for example can really benefit from this strong light, and many images of tropical seas are taken at midday. In other cases the high contrast can be used to creative effect.
The small shadows and strong light aren't particularly revealing of form, and the low saturation is another drawback. Most photographers avoid using strong midday light, however that doesn't mean these conditions are impossible. As with most things going against conventional wisdom can lead to unusual and creative solutions.