I'm a software engineer for a VERY LARGE tax company. All of this makes perfect sense.
He's trying to avoid the government paying out EIC (earned income credit) to people who already don't owe taxes and are getting a refundable credits in excess of what they actually paid in. This is VERY widely abused.
The marriage penalty is commonly thought of around our office as unconstitutional as it does undermine marriage. People have a reason to not get married because one spouse's income greatly exceeds that of another. When this happens the withholding of the lower income person is not enough to account for the higher tax bracket they are pushed into when they file jointly. Unless one or both of them had additional money withheld from their paycheck, then the couple likely has an amount due to the IRS.
15% is better than 0% after inversion.
Lastly, I die and leave everything to my only child. It's in excess of $1.5M in value and is now considered taxable. My child has to sell the farm ground he inherited just to pay the taxes. He/she cannot continue on farming and must find a new career and leave their home.
The F-15 Eagle: If it's up, we'll shoot it down. If it's down, we'll blow it up. -- A McDonnel-Douglas ad from a few years ago