Not true. WHS uses "Folder Duplication" --you can turn it on for individual folders, or entire drives, and it will keep shadow copies of your files on additional drives, so if you lose a drive, you do not lose data.
It's actually quite a well-thought out setup. You get to choose which data is important enough to you to keep dupicates of. You can also assign any drive you add to your WHS box as a "backup" drive (as opposed to storage), and back up your entire WHS box to it, or just selected parts, and you can do it easily. I have a 2TB drive connected via eSATA to my HP MediaSmart server, so I can grab it and run should the house catch fire.
After all, RAID isn't a true backup either. Screw up a file, you've screwed it up on any mirrored copies as well. Windows Home Server is incredibly easy to use. Someone with just a small amount of tech-savviness can go out and buy a preloaded WHS box from HP, Acer, or Lenovo, and have it up and running quickly. People who are saying "Go Linux", "Go RAID", or "Go with this exotic file system" instead are missing the point, and have probably never run a WHS box so they don't realize how nice it is to work with. MS made a huge blunder with this choice, make no mistake.