Always blaming the system is not productive. If the system has to be air-tight to get a usable result, you've already lost the battle.
I have no doubt that an attempt to make the tax system air-tight would result in an even greater degree of loopholes and bureaucracy. But laws are not air-tight. Case law and "common-sense" should prevail.
Shutting down the most egregious tax-avoiders (i.e. those companies who rely on untested laws) would quickly clarify the situation for all other accountants. Loopholes would be exploited once - accountants would not sign off the audits of companies using them in the future.
In this vision of the future the exploiting companies need not be punished harshly - exploring and testing the tax system could be looked on in the same way as white-hat penetration testing. "Thank you for bringing the loophole to our attention. You may not use it. Return any profit you made from it. However, anyone caught using it in the future will be face a much greater punishment."
Taxes are a necessary evil to begin with; they're a direct impingement on the freedom of citizens. Making the laws surrounding them so hideously complicated makes it much worse. No one's really asking for air-tightness, just low enough complexity that we don't have to have full-time professionals to make sense of it. Taxes should be easy.
The corporations in this case are not using obscure loopholes to avoid taxes. They're taking advantage of necessary complexities in the tax code: that it taxes net income rather than revenue, and that it taxes income reasonably related to the jurisdiction and not all income everywhere. What's complex is the situation: accounting for the income of huge multi national businesses that have customers and employees in dozens of countries, whose income involves transactions with pieces spread out all over the world.
Its like saying that the Windows kernel should be simple. Sure, as long as you give up decades of backwards compatibility and a multitude of hardware support you could make it simple. Analogously, the only way to simplify the tax code might be to give up on taxing corporations. But you can't jump to the conclusion that the complexity is unnecessary.
There are other means of taxing the citizenry and funding the government. Why should we tax the compensation for work, physical and/or mental, of the population? Better would be to narrow the compliance field to taxing consumption. And in the US we are generally voracious consumers (can speak for the UK).
Wrong. They are the price citizens have to pay for those freedoms. Want to have the freedom to use public roads? Pay taxes to fund their building and maintenance. Simple as that.
The same applies to businesses as well. Heaven knows how much public infrastructure Google is using in England. So why aren't they paying for it? (Not to single out Google of course.)