"It is because Harry suggested they take the cup together that Cedric was brought to Voldemort and got killed. But Harry shouldn't be blamed since it was plain to see he hadn't any idea what the cup was. It's just a terrible trap which…"
"No, it's not Harry's fault.
They both wanted the cup really badly and Harry was polite enough to share the price. There was no way he could have known the impact of that decision. Plus it was Voldemort who told Wormtale to kill Cedric,…"