I doubt there's a decent beer off licence in the country that doesn't do this. But if the alternative is the proprietor saying "Fancy beer doesn't sell" and pulling the whole range from the shelves, then I've no problem with the out-of-date selling. It would be nice to see more places offering old stock at a discount, and even nicer if this could be done on a bespoke basis, i.e. a policy of x% off any out-of-date beer you find.
The bottom line, I think, is [i:23wqh9er]caveat emptor[/i:23wqh9er]: always check the date, and if you don't want it don't pay for it.