Grom Hellscream

He didn't listen to Medivh when he warned about a greater threat coming to Azeroth. He and his allies accepted the demonic corruption plaguing the orcs, he betrayed Thrall and the horde giving himself to his brutish instincts. They corrupted Ashenvale and killed Cenarius. In the end, he wanted to redeem himself and his allies by helping Thrall defeat Mannoroth. If you think of him as a hero of some sort, he is instead a coward. He fled from the problems. Killing yourself doesn't solve any problem. Go, teach others how you were wrong and ask them not to repeat your mistakes, so your successors should not follow your same path of savagery and corruption.