Most Helpful Guy
I think he is saying that not to be hurtful to you but because it was a failed relationship it feels like a waste. He could look at it as a learning experience, which in turn would not be a waste of time. But he could still be feeling hurt from the time and effort invested and ending back where he started before being in a relationship with you. Thats my theory for now
Most Helpful Girl
Probably because he's hurt and disappointed it didn't work out.