I'm tempting the wrath of the ppruners here, but IMHO the reason Rule 5 is not as straightforward as we'd like is because the issues it attempts to deal with are not straightforward.
Everyone (I hope !) would agree that good judgement, solid airmanship, and good neighbourliness are the key issues about using non-licensed sites. If the world was a perfect place, we could end with that.
As an attempt to codify what that means, Rule 5 is IMHO not a bad shot. It focuses on what it is we're trying to prevent (damage to persons or property in the event of engine failure) rather than attempting to substitute for pilot's judgement. As the outcome in the case underlying this thread clearly shows, it is actually a pilot's best line of defence against small mindedness and nimbyism IF we behave 'reasonably' .
If I could add one final point, the reason I posted a link to the text of Rule 5 wasn't just to be glib it's that IMHO more people actually read the rule, rather than relying on other people's interpretations, then they'd be better equipped. If you know the rules then you can interpret them and fly with confidence rather than adopting the slightly hunted tone we often see in these pages.