Indeed, why else would I be so bored I would want to argue on the internet (although to be fair I met my wife in a food co where I was implementing a stock management system that I designed to minimise waste though ingredients going out of date)
Labs test the products and see how long they will remain safe to eat, the date on the pack is two days earlier than the last day it was tested safe to eat.
Ok so these days factory procedures are pretty good and they are checked regularly (especially by their supermarket customers) but what if it sat in your car for a couple of hours?
Also, scrapping/ignoring use by date might be fine for people who are 100% with it, but what about old people or those who live on their own but in sheltered accomodation, ?
The answer to not wasting food is to not buy it in the first place and then if you do, eat it within date, simple.