|Digital cameras have a permanently fitted ant-alias filter in front of the sensor to eliminate moire effects resulting from interference between fine patterns with slightly different orientations as commonly occur with garments, for example. The resultant pattern has a very different orientation and shape from the primary ones. Anti-aliasing by necessity causes a small amount of image degradation which is noticeable in enlarged form but manufacturers consider that preferable to the moire effect.
Landscapes, sports photography and most macro images are not prone to aliasing, while it can be a problem with, for example, fashion, and architecture photography. With wedding photographs and portraiture, it will depend on what the subjects are wearing, and it may be a factor in bird photography. So, for serious photographers it seems, as with lenses, should be a matter of horses for courses with cameras too.
Do you ever observe a moire pattern with your camera? There are moire patterns on images taken with my "old" 350D which disappear when enlarged, so maybe it was not produced in-camera.
PS: I tried to start a new thread on this topic yesterday but it disappeared. Hope it works this time.