Their nominal tax rates is not the issue. Allowing entire profits realized in EU to leave to the Bahamas through layers of companies incorporated in Luxembourg/Ireland/Netherlands is.
Is there some reason why wholly owned subsidiaries should pay income tax at all in other countries? I own assets in the US, but I don't pay income tax there, because I live in another country, where I pay income tax on my worldwide income. Amazon "lives" in the US (headquarters are in Seattle, WA), so why would it pay income tax in other countries? Its wholly owned subsidiaries are just parts of the whole, and should be taxed as such.
