This technique is very helpful for another one situation. If you are working with big resolution picture which has a lot of description (for example maps, fonts), details and you will have to decreasing resolution to less picture. Maybe for posting in web the details, descriptions as types will be blurred and washed because of removing some pixels from picture during changing image size down. Than you can apply sharpen filter for recovering those details from your art work. I tried this when I was working for APO, designing the map for their online game. I posted it below.
Whiteout sharpness the map looks bad and names of location weren't readable. It was very noticeable from closed distance after zoomed image in.