Let me spell it out plain and simple:
Rule 34 is just porn. Ordinary harmless porn. Porn for he sake of porn. Nobody takes it seriously except the haters, who are totally missing the point
Cupcakes is just shameless gorn. Not even a well-written gorn-fest either. It was never scary, just disturbing, and a major sufferer of what 4chan calls "Trying Too Hard"

1. Complain about pony porn
2. Use picture of pony wearing more clothes than usual
3. ???
4. Profit!!!
(also, I heartily agree with TARNunit9. Give it a rest R34 haters, you're only helping to keep the thing you hate at the front of everyone's mind.)