I'd say the reason it was added to the Harsher in Hindsight pool was because Satsuki betraying her mother in Episode 17 and rejecting her mother's assimilation plot.
HubiKoshi said: Or because Ragyo is most certainly NOT a good and loving parent she is portrayed as in these pictures
That's fo shizzle, she's asshole enough to push BOTH Gendo Ikari AND Shoe Fucker resp. Shou Tucker off the winner's podium for the shittiest-parents-prize in animé history!