The very idea of carrying handloads for self-defense purposes in 21st century America is ridiculous. While the liability argument may be debatable, the idea that you are going to produce handloads that will equal the quality and reliability of premium defensive or duty ammunition from one of the major US manufacturers is a nonstarter.
In days gone bye, when factory options were limited and distribution was not a click and a credit card away there was a certain logic to rolling your own for serious purposes but as they say the past is another country and they do things differently there.
As to the loading itself, BB I hit the nail on the head. The attraction of wadcutters as a carry option is reduced recoil hopefully resulting in better shot placement. There are no magic bullets. Assuming baseline terminal ballistic performance is met shot placement trumps everything in the real world.
People don’t like to hear that it’s the Indian not the arrow because they don’t like facing their own mortality. What if they miss? The fact is no matter how skilled you are the outcome is never certain and there is always an element of luck in any armed confrontation. People don’t want to face that reality so you get magic bullets, ballistic Wobblies etc as variations on the classic lucky rabbits foot.