I mean he hasn't lifted his country above it's level often enough (or at all). We're talking high standards here, but the best players are the ones that raise the level of the players around them, and push the team beyond what they'd be capable of without him. Certainly, it doesn't merit the kind of plaudits he's been getting over the last few days, as though it's the end of an era. What era? What difference did Ibrahimovic make?
To put it another way, would they have achieved anything less over the last 10 years without him? If you can't distinguish between what a national team has achieved with a great player to what they could have achieved without him, I think that is a good definition for failure (and I use the term loosely) on the international level.
I suppose using that definition, Ronaldo and Rooney have also both been failures on the international stage (an opinion I would also probably agree with).
Also, you know, I just don't like his self-obsession and delusions of grandeur, which may be biasing my opinion a bit.