Hi Ivor,
The other issue is that you may wish protect your system to prevent anyone else changing your settings accidentally. This can easily occur when several PAWs are all running together on the ground if someone decides to make changes to theirs, but doesn't check carefully that they are connected to the right unit.
I don't use the password option myself, but have had experience of just this sort of thing happening to others, which of course means 2 aircraft then take off with a completely different setup to what they are expecting.
In this case the other option if you don't want the hassle of a password is to change the PilotAware SSID to something more personal such as your Aircraft Reg.
Page 40 of the User Manual explains in more detail.
Regards
Peter