If you build/design your products here then you use EU's trained labor, EU's infrastructure, EU's legal system, EU's defense, etc. then you should pay your fair share to support these facilities that help you be a billion dollar corporation.
But I have a hard time understanding how politicians figured that countries with widely varying tax regimes inside an economic union would work out for the countries with a taste for high taxes.
It makes no sense to me. Of course companies are going to choose the most favorable location to incorporate. Counting on companies to be "fair-play" or whatever the politician word-of-the-day is seems completely braindead to me. Unless there were some kind of backroom deals going on, which wouldn't surprise me one bit coming from the EU nomeklatura, and now they're trying to conceal it by blaming "the rich" / "corporate greed".