ConsciousDonkey said:

Except that princess isn't a main character and wasn't arbitrarily turned into an alicorn just because company executives thought it would sell more toys.

No, you're quite right. Cadence is a character who only exists at all because company executives thought a princess wedding episode would sell more toys.

I have nothing against her, but if you have issues with Hasbro meddling with My Little Pony, you really can't hold up Cadence as being anything more than the exact meddling you seem to despise.