SCALE LENGTH DIRECTLY EFFECTS THE LOUDNESS OF THE GUITAR; THE LONGER THE SCALE THE LOUDER THEY GET.
Not true. The quality of sound may well be different, but not the loudness in general.
SHORT SCALE GUITARS COMPROMISE THE BASS RESPONSE
Not true. Provided the luthier does not treat the short scale guitar design as an under developed little brother of the real thing.
THE SCALE LENGTH DOESN'T MATTER. I HAVE SEEN TINY PLAYERS DO FINE WITH THE LONG SCALE, YOU JUST HAVE TO DEVELOP THE STRETCH.
A direct relation of the no pain - no gain school of thought. I have watched numerous guitarists injure themselves or simply under achieve their potential, all because of a poor guitar fit.
"MANY MAKERS OFFER "SHORT-SCALE" GUITARS OF 645 MM OR 640 MM. THESE ARE SO LITTLE DIFFERENT THAN 650 THAT IT IS ALMOST NOT WORTH THE TROUBLE."
I am one of those "many makers". Actually I have been promoting the concept of reduced scale length and it's many benefits for about 18 years. Even though I am certainly capable of constructing a" loud box" of any scale, down to any size, like 613.5mm for example, I feel that it is irresponsible to belittle the impact of the difference of 10mm when in my experience most players can pick out a 2mm difference. Hence the conservative approach.