As Floogie says, it's simply not as black and white as this.
In the case of Amazon (using 2010 figures):
The Luxembourg office employed 134 people, but generated turnover of €7.5bn (£6.5bn). In the same year, the UK operation employed 2,265 people and reported a turnover of just £147m. According to the SEC filings, UK sales that year were between £2.3bn and £3.2bn.
It's clever business and it's not Amazon's fault if the loopholes are there to allow them to play the system, but if you believe that then you can't use the opposite argument against the Greek individuals that find ways to play the Greek system.
Hiding and concealing income is different to moving income.