I don't think unbanning people will help much. People that still want to play just need to come back with a new account - permas have never really been true perma's here. The bans are only really a deterrent. What would happen is a bunch of angry guys come for a week or so and dick around until they get bored/banned and we're back to square one. Only the worst guys get permas, they have to screw up baddly multiple times - you will get cheaters, scammers, trolls for no real benefit
The population issue is a result of people not enjoying the game, playing other stuff, wonky gameplay, real life etc. Unbanning guys would be scraping the bottom of the barrel