There's a lot of truth to that.
I hate that John's been around 50years or so and really STILL hasn't been developed well. He has very little in supporting cast, friends, enemies, and life outside the GLC.
It really seems like if they were going to tell this story with Sinestro and Evil Hal... they SHOULD have used Hal. If they want to use John... find or create something that will be uniquely John.
When was the last time the Mosaic world was mentioned? Didn't he have any enemies there? Couldn't there be someone who was on those cities gain powers and hold a grudge against him for keeping them there?