you are a cynical lot.
Bloody hell, a company tries to offer a useful service to its customers and all you can do is whinge.
Ocado delivery men bring the shopping into your kitchen. I imagine that if if any scam is to be conducted its around getting access to someone's car keys. I expect most people who use them get their delivery same time each week. Therefore if I were a scumbag thief who wanted to steal someone's nice merc or bmw, and to do so I needed to get access to the keys, what better way than being the ocado delivery showing up an hour early. The drivers often have an assistant so the scam gets more of you further into the house compared to a meter reader. Handy if you need to use a bit of threat and force to get the keys.
if ocado abuse the mobile number lists they collect then they will very quickly piss off their customers - a demographic you probably wouldn't want to upset.