While I agree that the characterisation of KotFE is shonky, I think the OP is dead wrong about the reasons.
"Characterisation" does not mean "long dialogues like in Fallout" (which, by the way, was in no way fully voiced - I seem to recall that exactly zero of your companions were fully voiced in the original, and only Sulik, Marcus and Myron were voiced in 2). As the OP points out, the game quickly and efficiently establishes the personalities of the major players and that is what caracterisation means. The fact that you don't get to sit them down and ask them where they grew up or what weapons they're skilled with doesn't make them less well characterised.
Where the characterisation falls down is in the character of the PC, where the plot basically assumes that no matter what class you are and how you played your original story, you're this generic Hero type. Characters who are loyal to nothing but credits, or who have devoted their entire lives to spreading pain and carnage to everything in front of them, or whose entire modus operandi is staying in the shadows are suddenly thrust into this position where they're basically Commander Shepard, standing up and telling a room full of Jedi and Sith that We Fight Or We Die.