Because it's time for Hashirama's Comedy Hour!
Sasuke asks Hashirama what is village and shinobi given how Itachi betrayed and murdered his own clan and went into exile for the village. Sasuke states that based on Hashirama's answer he'll either destroy the Leaf or do something else. The Uchiha-hating Tobirama starts to power up and threatens Sasuke, but Hashirama unleashes his aura and gets his brother to back off. Hashirama tells Sasuke to get ready for a long story, but Orochimaru tells Hashirama to be quick about it because of the war going on outside. Minato can sense Naruto and Kurama are fighting together. Tobirama tries to leave but is restrained by Orochimaru's jutsu, and Tobirama realizes Orochimaru has Hashirama's cells. Orochimaru also restrains Hashirama, but unlike his brother Hashirama is able to break free and move on his own. Hashirama agrees to answer Sasuke, and he sits down and starts at the very beginning when he fought Madara.
Looks like the Sasuke Q & A segment is going to take a while, as Hashirama doesn't quite start answering Sasuke's question until the end of the chapter. Orochimaru probably made a mistake mentioning that there is a war going on outside and now after Hashirama answers the questions the Hokages will try to break free to help the shinobis battle Madara. Hashirama finally shows why he is the "God of Shinobi" by staring down Tobirama when Tobirama's Uchiha-hating ways went a little far for Hashirama's liking. It'd be funny if Sasuke and Orochimaru decided to help Naruto and friends defeat Madara and Obito, but Sasuke is unlikely to change before he fights Naruto and Orochimaru always has his own agenda. I guess we'll have to patiently sit through story time for the next few weeks.