Because you can.
i recently heard on a podcast that smartphones are bad as music players because they are very distracting. especially for athletes. a single notification or message can lower their performance for minutes. music on its own can however boost performance.
as most mp3 players are moving to using android as their main OS and requiring wifi, location and whatnot, i have learned to appreciate the simplicity of the first few generations of mp3 players. so i really like what this project is doing for some reason.
If you insist on buying a new one, the Hi-Fi community still makes audio-only music players as well.
My main Rockbox'd unit is an iPod Video (5.5) with an iFlash Quad (up to 4x microSD cards) and a 2000mAh battery. Not the most expensive project, but not as cheap as the Clip+.
My guess is that the parent is talking about the Sansa c200 or something similar.
The best iPod Video is the Enhanced / 5.5 that has the 'search' item. An 80gb version of this also has more RAM, which I don't think is utilized at this time, but it might down the road. This may not be accurate now, but it was a few years ago.
The 80gb will come with the fat back. If you do the mod I did, you can use the slim back from the 30gb.