If you are advertising that your door is unlocked, and the precedent is to enter unlocked doors - as it is to connect to open networks, then yes. Permission in such a scenario is implied.
You make these analogies attempting to equate an advertised open WiFi network to an unlocked home, while ignoring the precedent around both of those things.
It is expected that people connect to your advertised open WiFi network. It is not expected that people wiggle your doorknob to check if it's unlocked or not. If you put a sign on the door advertising, "the door is unlocked!" then I wouldn't be surprised when someone mistakes that for "come in".