Lois figured it was a safe assumption to believe that maybe Superman could rid the city of its darkness. She wasn't quite sure the extent of his powers. She had heard the stories and came to her own conclusions about what he was capable of, but she thought the question was a fair one to ask. It was more to test his judgement of the situation and see what he felt about it. If he reacted superior to the task then perhaps the people of Metropolis needed to find a new hero. But he didn't. Superman gave the answer that Lois was honestly looking for. He hadn't boasted about his abilities, nor was he beyond help. She liked that. It meant he was willing to fight for them and get others to help him in the task of cleaning up the city.
When Superman mentioned making Metropolis his home, Lois couldn't help but smile. "Oh good. Well, I think the people in this city will welcome you to stay here. It's not every day that a man like yourself opts to stay in Metropolis." Which was the truth. Nobody with special talents like his was fighting to help save their city.
"Any reasons you like this city?" She inquired, honestly just curious.