Changes to legislation take time.
Certain parties have had payments from Tesco before and don't feel the need to make changes to laws all that quickly. And every time a hole is closed, some clever cunt at Barclay's or KPMG or PwC finds another one.
(
Colonel Boris "...a desperate Buzzfeed imitation...",
Sun 1 May 2011, 14:15,
archived)