The stall detection only works over a limited speed range and it is updated at most once per full microstep. So it wouldn't be accurate enough to home a Cartesian printer.
EDIT: you can use stall detection to home a Cartesian printer if you don't need the home position to be highly accurate. This is now covered in the wiki.
It might be possible to use stall detection to home a delta printer if you follow homing with delta calibration using a Z probe. In fact you can do this without stall detection, you just need to reduce the motor current during homing (M913 command) so that the motors don't exert too much force when the hard stops are reached.