Unfortunately Obito did far worse than Nagato, since he was basically the one over Nagato and orchestrated a lot of what went wrong throughout the story. They both did wrong, however Obito was just the bigger puppet and takes more of the blame, same with Madara. I still think it was right to forgive both of them since at least they felt sorry afterward; it still doesn't make what they did right and they're not redeemed but forgiven if that makes sense.