Ik think that people are making too much of the fact that he was a bounty hunter and worked for the Empire, that does not necessarily make him bad or evil or without a personal code of honor. Sure, he worked with the Empire, but he's a bounty and the Empire was the lawful government, so if they offer a bounty, why wouldn't he take it? It's not like the Rebelllion was going to be offering bounties for, say, Grand Moff Tarkin; since they're operating underground, it's not like they could do things like that. Now that the New Republic is in charge, bounties and bounty hunters are still a thing, nothing's changed except maybe the New Republic itself doesn't issue bounties, but it certainly seems to be legal, if frowned upon.