Madara was a bitter enemy of senjus and hashirama knew it. Everytime he defeated Madara he didn't finish him, neither he let tobirama do that.
If he didn't want to kill Madara b/4 then why try to do it at VOTE. So he realized at "that" time that he made a mistake b4 by letting Madara live? Thats a really stupid act to realize it that late
Neither generous, nor foolish. Rather, he was wise, and I think only a few people can understand that. I mean only people who try to see the real life side of the manga besides actions, rivalry between Uchiha and Senju.
First, you need to understand that before Madara, Hashirama was a god who could spank Madara whenever it was necessary. So why kill him? Second, even if he killed Madara, someone else would have appeared - example Sasuke. Third, clearly, as Hashi said, they were some Uchiha who wanted the truce but also were Madara's fans or relative (lovers, friends etc). Thus, killing Madara would have turned them into potential enemies.
There are many ways to see that Hashirama was correct, and I think only people who read the manga for the fights or the coolness of the drawings can miss these reasons.
