After Assault on the Broken Shore, Thrall tells the Shaman the explorer that since Garrosh was killed, he's felt like Doomhammer was nothing more than an unmoving piece of equipment in his hands, and that the Elements had left him.
He confided to Orgrim that the Doomhammer had brought him closer to nature, however it was now a useless tool with his.
Through the years, Thrall wielded the Doomhammer with honor and integrity. Thrall was a conflicted person following the murder of Garrosh Hellscream. The nefarious warchief. This internal conflict was manifested in the Doomhammer and the Doomhammer. Thrall believed that the Doomhammer was an act of revenge, because it was previously a symbol of justice and virtue.