Doktor and Centaurus
You miss the question: why do Boeing continue to have the option...if it's never, ever, ever to be used??
Could reduce the cost of a Boeing 737 by a $$ or two for a "simpler" on/off autothrottle.
Centaurus - generously - by stating the FCTM statement that is not NORMALLY recommended demonstrates that those

who have deseigned and built the aircraft (Boeing) have it there for a reason.
He also has indicated problems that have been observed - by

pilots who have not been properly trained by a

training department.
The question remains: why do Boeing continue to have the option...if it's never, ever, ever to be used??