that's just it, it's NOT redirection in Linux, you are wrong. It's mounting that partition right there in the tree. Your filesystem tree should not be tied to physical volumes.
As far as USB drives/floppys go, yes, the user needs to know they are saving it to them, but when you pop it in, it usually automounts and opens a window, just like in windows.
The linux installer defaults to that if you have other partitions you are not formatting (and specifically NTFS/Fat32 partitions) because where else should it put it? It puts physical volumes with existing data that you don't want touched under the /media directory, where it mounts other disks/usb drives/etc. So from /media, you have usbdisk, drive2, etc. This is because they are not part of your OS. Now, if your /media/partitionfromthisdisk is meant for /home, it's pretty damn easy to go and change the mount point, be it during install time, or after install time. Windows won't do it during install time, unless you use various tools to create a customized disk, so you have to do it after install time, and it can be painfull to move the entire Documents and Settings folder to a new drive.
This is all moot though, if you really think that linux making /home on a second partition/network drive is redirection, as it means you do not understand what's happening in the lower levels of the OS.