Improper use of the raster resampling environment settings can lead to problems with rasters. If the default option NEAREST is selected for continuous data then it can result in artifacts that appear as horizontal and vertical striping. The striping is especially problematic for DEMs, hillshades, slope rasters, and flow direction rasters and can even affect watershed delineation. Often these problems can be hard to identify and deal with at a later date. I'd suggest that ArcGIS should be re-designed to be smart enough to detect the proper resampling technique. If the data are integer then NEAREST could be the default, but if the data are floating point then BILINEAR or CUBIC could be the default.