You're getting there. He wants apple taxed in the us. Apple is now for a major part taxed in Ireland because it's cheaper than UK, France and other options.
Please read again and understand. "less reason to file in countries with lower tax burden like Ireland and more in the country where the value is created.".
Hence the 15 pct minimum requirement. A more level playing field would result in less reason to file in countries with lower tax burden like Ireland and more in the country where the value is created.
I think there is a mandatory 30 days notice to Congress required for this. And in that notice 'cause' must be mentioned. Firing st will as seems to be the case here is most likely not allowed.