At a global scale, there is only law. If countries want more taxes, they have to change their laws, and be prepared to deal with the unintended consequences of those changes.
Most businesses prioritize their own market value, and subordinate all other motives, including apparent political posture, towards maximizing that one metric. Therefore, they only pay taxes to avoid the negative effects of not paying taxes, rather than out of any perceived moral obligations.
The companies are there because the optimization process that involves jurisdiction shopping determined that establishing a business presence in Ireland provided greater benefits than the other options. There can be only one "best" jurisdiction for any given business entity. Complaining that someone else's seems to be better for more entities than yours is just sour grapes.
If you can't compete on a tax cost basis, there are other ways to attract business: a zero-corruption bureaucracy, privacy or secrecy for principals, reduced reporting requirements, reduced time from initial filing to practice, ironclad and proactive intellectual property protections, strong infrastructure, rock-solid stable units of accounting, or any of dozens of other points that may provide business value that more than compensates for the tax burden.
So fairness is a red herring. It is the objective value that is provided in proportion to the taxes taken that determines whether taxes are "too high" for a business to bear.
Immensely wealthy multinational corporations have a lot of money to spend on lawyers and accountants, so while these companies are probably not evading tax the avoidance schemes they come up with are sometimes not legal requiring them to repay.
Don't forget that tax is part of law and so there is what's written and how that's interpreted by the courts. Until you've had case law there are areas of uncertainty.
It's not a hard number but perceptions of fairness are certainly important in how democratic countries formulate tax law.
http://en.m.wikipedia.org/wiki/Taking_the_piss (first sentence: unreasonable).
Perhaps you'd prefer to use the term 'electorate'.
Regardless, the meaning was clear and your objection rather ridiculous.