End of 12.5% corporate tax

[schmittel]

So it looks like the government has conceded the inevitable and we'll have to get out tax rates in order - for the big boys at least: Ireland has ‘assurance’ it can keep 12.5% corporate tax rate for smaller firms

Apart from the obvious point that supposedly we already had assurance that taxation was entirely a matter for the Irish government to decide, something else jumps out of the article:

Mr Varadkar said the increase in tax rate would reduce the State’s revenue by about €2 billion a year based on “existing projections”

If I understand this correctly, government projections are saying if we increase the tax rate by 2.5% on the country's biggest corporate taxpayers our tax revenue will go down?

Our same government, as well as numerous talking heads, employees of MNCs and various other well informed experts, are fond of telling us that our economy is not built on house of cards because these big MNCs are not just here for the taxes.

So, if these MNCs are not just here for the taxes how is that our corporation tax revenue will go down if the corporation tax rate goes up?

What am I missing?

[Del.Monte]

Isn't it because taxes will be paid in the countries where the products are made rather than where their HQs are based?