You'd think he'd want to reconnect to the humans he knows to remind himself they're not all fearful, jealous, fragile, mass murdering collaborators. Not y'know, go walking about, on their level, having them go all 'Oh Superman, you're the greatest, even though we just murdered the home you never thought you'd see again and all the people with powers just like yours. Now, could you totally get my cat out of a tree?'

(I'm just guessing btw, gave up on DC a while ago.)