Not sure if this should go in here or the travel products forum.

Did a few UK domestic recently with a checked in bag and my hand luggage.
Passed through security into the airside shopping areas.
In airports such as Heathrow, Gatwick, Edinburgh etc, there is always a shop selling luggage such as Samsonite, Tumi, etc (think there is a landside one as well as airside at Gatwick though)

So, why do they have these shops airside? Unless you're carrying no hand luggage or have the desire to buy a new piece of luggage and transfer everything from it into the new one, keeping the original which means you could have 2 x22" cases as hand luggage or throw away the existing luggage (which really isn't possibly due to security risks), surely this is the completely wrong time to be buying this sort of thing?
Personally, I would want a new case or buy prior to checking in my bag or getting somewhere near the gate.