well, he doesn't particularly care either way, tbqh. They were a source of entertainment back home, but just a few of many. He's interested in seeing what Mikado plans to do, see if he's going to try to mobilize a portion of camp anonymously like he did Ikebukuro (deliberately or not) and if Kida plans on telling Mikado about himself or not and what KIDA's going to do, with Aoba in camp and ~knowing things~ and... Izaya's just watching. Mild meddling and trolling, but mostly he's keeping Kida paranoid by not...doing much. Because making Kida wonder what he's up to is funnier than actually doing something.