B737 Autothrottle....yet again
Well...one thing is to have the option, (which is by the way NOT RECOMMENDED), and one thing is to have it "included as STANDARD"
I think latetonight is right...some years ago it was possible to fly the approach manually with the A/T deselected. You had to be aware the during the flare, there is no gust protection and the risk is either a hard landing or a go around. After a few accidents things changed.
Since nowadays manuals are written by lawyers Boeing decided to leave the deselect mode available but suggested not to use it.
Therefore now its use is NOT STANDARD.
This means you can use it but if "something" happens...during landing,you will have to explain yourself why you did something NOT RECOMMENDED by the manufacturer.