After some consideration, I conclude this is "a good thing"
If your parcels go to a neighbour, and you don't receive them, you complain to the sender, who sends another and retrieves the cost from the PO for failure to deliver. Bit annoying, introduces a delay, but ultimately you should still get your stuff.
If your parcels DON'T go to a neighbour, and you DO receive them, you sell them on ebay (or for preference at a car boot sale.. you know, less traceable) complain to the sender anyway, who sends another and retrieves the cost from the PO for failure to deliver.
If a neighbour's parcel comes to you, you disavow all knowledge of it, and again sell it on ebay/carboot. They complain to the sender, who dispatches another and retrieves the cost from the PO for failure to delivery. Bit annoying for them, but hey - ultimately they get their stuff.
And all you have to do is be a complete bastard. It's like i'm pissing in the plant pot at that party all over again.
Hey presto, 6 months down the line and no-one users RM for anything but postcards any more, and our evil overlords get their wish and privatise the whole business. HURRAH FOR PROGRESS!!