Is this the case, though? How much profit is generated by Irish Apple customers compared to the giant amount of tax paid in the country due to Apple being there?
Not so giant. You can check https://en.wikipedia.org/wiki/Apple%27s_EU_tax_dispute which is updated with the latest ruling. The dispute was about taxes from 2004 to 2014. I wonder how much they'll owe to Ireland for the next ten years.
> Apple only paid an effective corporate tax rate that declined from 1% in 2003 to 0.005% in 2014.