User blog comment:TheIrregularOne/Why not OVAs?/@comment-17714224-20131228121151/@comment-17714224-20140104193000

To further illiterate sheer difference between most story arcs and the WW3 arc is that most story arcs only last 1-2 1/2 days even the first season only had about 5-6 days worth of in universe screen time and the WW3 arc is 12 consecutive days going by that logic you could fit two seasons within that arc. The Daihasei Festival Arc and Academy City Invasion Arc both  lasted six episodes each were two volumes long, so again the WW3 Arc would be able to fit a bare minimum of 18 episodes and with some well-placed action and drama padding you could easily extend that. Plus the anime needs to take time to explain many of the different aspects that it never got around to that seem to confuse people who watch the show casually and it's the perfect time since everything is building past the climax of the story.