I'm usually against "big governement", and generally against the EU, and more on the side of "laissez-faire".

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".