Starbucks to pay tax on losses in uk

Makes perfect sense that Starbucks should pay tax on losses after years of not paying tax on any profits. The amount though – £10m – seems to be a bit arbitrary, in the manner of someone walking down the street who looks for some reasonable amount to give to charity. Instead of giving money to the taxman, which they have no obligation to do, why don’t they give a discount to their customers who maybe won’t feel the need to boycott them for never having paid tax?