Since we know Ku can sing, then why is autotune a huge deal? It's there for an added effect. Honestly, autotune can really help create the atmosphere for a song. It's not always there to hide flaws.
I myself have always been a fan of the autotune sound. Take a listen to this DJ Amaya remix. This was back when I didn't know the term for that effect on the vocals was "autotune", but I always thought his mixes with this effect gave off a much better atmosphere to the song:
Vocals @ 1:48
I also loved his remix for "Hana" with the autotune effect.