Very few images require the array of adjustments and creative tools available in an image editing application like Photoshop. Some images are fine just the way they are and require little or no adjustment beyond what the Raw encoder produces from the data as the image was shot. The vast majority require only minor tweaks, maybe small White Balance and Levels adjustments, Sharpening, and possibly some blemish retouching. A few images, say with exposure problems or color casts, may require more intensive care.
Aperture provides all the tools you need to carry out these everyday darkroom tasks as well ...