It obviously makes sense to try and sell the shorter date stuff first... As long as it's within the legal requirements there's no reason it shouldn't be sold.
As for waste it does depend with me I once ate a battenberg cake which after I bit in a load of maggots came out. After that I am probably over cautious but I did eat a tin of beans 3 years out of date.
To the OP. it's called rotation! If they put the newest products at the front then by the time anyone picked the ones at the back they'd be out of date.
As you've found out already if the date isn't good enough take from the back. If that isn't good enough then try frozen food