Capital prices are more about relative competitiveness than absolute competitiveness. If every hundred dollars makes $4 instead of $5 next year because of closed tax loopholes, and your investment now makes $400 a year instead of $500 because of those same closed tax loopholes, then your investment hasn't changed price.

Depending on the PR costs to support these tax loopholes, Google may even be better off closing them - so long as the PR costs are expensive enough, and the tax loopholes benefit everyone equally. The whole industry makes less money, the government gets more money, and Google saves on PR costs, providing a relative advantage and increasing their stock price.