The main reason I posted this thread was because two months ago, someone tried to log in into my KDP account, and the only thing that prevented full access to my account was that I had Two-Step Verification since 2014. I know of the attempt because I received a code that I didn't require. At the time, I thought that it was an error, and I didn't appreciate being awoken in the middle of the night by the text sound.
Now, we all know that Amazon had a data breach, and our information is out there.
It's a personal choice like everything else in life. I'm just sharing it in case somebody didn't know about it, and could benefit from it.