That would have been compelling, explain why his world was destroyed in the second movie and why he was the “mad titan,” all for basically zero extra exposition.

He was driven into an insane fervor by the callous destruction of his world and the apparent indifference of the universe. He decided that all life needed to suffer, as he had suffered, for universal understanding to form. It even carries a tinge of the self righteousness that the “im making sure there are enough resources for life by killing half of it” does.