I agree this is another prime example of awesome idea, horrible conception.
The idea of having a bunch of different horse characters, all recognizable by name, is a great one. Especially since you can buy hair and outfits for them separately and switch them around. And having a horse for each birthstone of the month, great idea! Too bad the molds just look too weird and unrealistic for my taste... >_>
Now WHY can't Hasbro get this idea!? Why can't they put out fewer repeats of the Mane 6 and instead put out more accessory sets so we can actually play with the ponies we have? Can you imagine fashion-outfit sets sold separately for the fashion style ponies to wear? How awesome would that be!? We haven't seen fashion wear sold by itself since the G1 days, and I don't know why Hasbro never brought them back.
I'm not saying necessarily that MLP need interchangeable hair, but little accessory sets would probably sell very well, especially with little girls. And if they made outfits like the ones the characters wear in the cartoon, they might be popular with show-fans and collectors as well!