Why not? Prices have fallen by about 15% since the August 2008 high. When you think about it, the wine in the bottle has not changed. In fact it may well have got even better.
The only change is the level of confidence. I always thought that you sold at the top and bought at the bottom. Remember nothing lasts for ever, prices will neither keep rising nor falling without abaiting. Do remember that the tax benefits have not changed, they are still considered wasting assets and therefore not chargeable to capital gains tax. In the end you can always drink the wines. You could find no enjoyment looking at your HBOS share certificates