[Levin]

Why commemorate someone who had depression and took his own life??

Because he was well-loved by the masses. He became well known after he was exiled from the court by the Chu King and started traveling among the masses.

He was exiled as he opposed relationships with Qin. And unfortunately for Chu, he was correct as Chu was later conquered by Qin. He committed suicide after learning that the Qin army has conquered Chu's capital.