Remember when Viktor was disabled?
He had a bug where if Annie is on opposing team his ultimate would disable hers. Mind you, it was pre-rework when Viktor was a rather obscure pick and Annie wasn't at the peak of popularity either. Still, a bug which disables an unpopular pick's ultimate when facing an even more unpopular champion was deemed game breaking enough to disable him...
...but Azir having no ult consistently is OK I guess. Totally not game breaking for him. Who needs an ultimate anyway? Not like his opponent will have one or something.