That's because Karma was literally a completely different champion in 2011.
One that Riot ignored as hard as Yorick. Never put on free week rotation after her second week, not a single slight change that put her in the patch notes or anything. Then they deleted her and made a new champ with her name (different looks, thematics, and backstory even) and her kit was so underwhelming that they needed to give her repeated hard number buffs just to make her playable.
They've tweaked her mechanics a little since then, but I guess this is the first time that Riot has deemed that her raw numbers are finally too high and decided to hit them a little.