I think why we have here is a classic example of "that's no use to me so I don't see the point"
For large families, people who live cooperatively, people who invest in a chest freezer the crazy offers that are sometimes on work out very well and do not result in wastage.
If these people were forced to buy 50x individual packets then the wastage would be in the unnecessary packaging.
It does generally work out better value to bulk buy and yes some people are seduced by this and waste the food however I would argue that rather than reducing everyone options to bulk buy to focus should be on educating people
Firstly in how to use up food that would otherwise go to waste and secondly in the value of sharing.
In twattys example (assuming she does not have a freezer) does she perhaps have a neighbour or neighbours dog who would be very happy to receive 3 sausages a week?
I live with a toddler and cannot use the about of potatoes sold in the big sack at lidl. However the difference between 1kg and 5/10kg? Is minimal. So I buy the big sack and give as many to my mum as she can use, as many to my friend as her family can use, batch cook to use up as many as I can use and still put some to compost (even though they are stored correctly)
Other options would be to half the bag and offer them to your school kitchen, the care home, a nursery, a love food hate waste scheme or turn up at a community group aimed at older people and offer them out.
Its more effort than throwing it in the bin but would do wonders to increase community feeling in your area