I feel like the people in question just cheated as a way to quit the game, with no desire to play anymore. I disagree with this method and think it's stupid, but that is just my opinion. This game is very addictive and there's no doubt that they'll probably have the urge to play again.
When you cheat, you acknowledge that you will suffer a maximum ban. Justice has been served really, they got what they acknowledged in the first place. There's no excuse, considering the huge bantimes that have been given before to people who committed the same cheat.
As for coming clean about it, eh, I suppose perhaps a reduction would be a fair way to deal with it, but at the end of the day, it doesn't take away from the fact that they broke the terms.
The amount of people doing it over the last few months calls for bantimes like this.