Whether you can safely exist with an unsecured network will depend primarily on where you live (or where you’re operating your network). Only if you live miles from anyone else and far from the road can you begin to feel secure running a network without encryption.
Even then, you will need to consider who may have access to your house that you don’t want to have access to your files. Think house guests, teenagers’ friends, cleaners, construction workers, etc. If you never have anyone in your home, then it may be OK.
But it’s still safer to secure it. Better safe than sorry!
