And not for the seemingly most obvious reason - In the original analog Prophet 5, the keyboard player would manually turn dials for oscillators, filters and more. The beauty of it was that it was never exactly the same any given night. With Digital and MIDI, it will be exactly the same, and even using a controller with an emulated vst, it will never have the randomness associated with the original physical keyboard. One of the greatest beauties of old analog gear was that it was not perfect.
Ask anyone who owned an original Mini-Moog.

 

This question should be addressed and answered by Gregory Scott of Kush Audio
he release his own plug based on his own engineering knowledge and also builds real hardware units too

check him out on youtube
PeaceR