It’s a shame, that even today people still use nearest neighbor resizing in GUI designs, especially in places then it’s not suitable. Taking into account that Lanczos resampling usually offers far better result at no cost (for static images) and even linear filtering outperforms nearest neighbor easily.
Just to make you see what you might be missing I share a couple of images, resampled (downsampled) with different algorithms:
Original PNG image (once again from Tango) and two smaller versions: Lanczos and Nearest neighbor resized:
Now let’s see some OS X wallpapers:
The difference is pretty obvious: “nn” spoils images by making them blocky, distorted and ugly which is arguably an advantage.
So, the tag is simple: unless you know for sure what you’re doing, do not use nearest neighbor resizing as it’s a fast way to spoil image. Also prevent usage of this mode by programmers (in many cases they use it without a real need) creating applications by your sketches.
Coming back to the title: resample, not resize; resample not, resize and not the opposite 
