you mean bland main guy, guy who gets mad at main guy for no reason, guy that loses his eyesight off screen and has to yell at guy who gets mad at main guy for no reason to stop being mad at main guy. And Prompto, hes pretty cool.
Then a bunch of irrelevant side characters, and a villain with good potential.
This cast blows
Noctis: Loose, doesn't care for much except himself and Luna until he gets put in his place by Gladio. Becomes REALLY awesome, resolved and bad ass ten years later.
Gladio: Strong, loyal and always frank towards Noct in difficult times, have a burning passion for CUP NOODLE. (lol)
Ignis: What seems to be the mind of the group, calm and strategic and a great cook!
Prompto: Like you said, he's awesome! Lively, curious and a great photograph, deeply scared for caverns.
Honestly, I think the main cast is filled with personality, anyways, it worked on me, they grew on me, or else I wouldn't be on the brink of crying during the ending. I can understand if you didn't find everything I saw in them during your gameplay though, but I think you have to play on the defensive from the get go to feel that way.