My Little Pony: Friendship is Magic is a highly popular show with growing popularity each and every day. There is an incredible fanbase that not only includes young children, but teenagers, young adults, and even adults as well. A lot of them, like myself, love plush toys. But the plushes Hasbro makes currently are inaccurate, save the eyes and cutiemark, to what the characters in the show look like. Many have pasta-like hair or frazzled "life-like" hair, such as this Pinkie Pie: http://www.krazykingsoftoys.com/images/detailed/1/My-Little-Pony-Friendship-Is-Magic-Pinkie-Pie-Plush.jpg . This is definitely not what Pinkie Pie looks like in the show, and fans are noticing.
However, many fan-made plushes look very show accurate, such as the Cutie Mark Crusaders in the title image.
Unfortunately, when these plushes go on sale, they reach up to hundreds of dollars and in not-so-rare cases sometimes pass a thousand. Most of the fans in the MLP:FIM community do not have hundreds of dollars to shell out for a single plush doll.
Based on these prices alone, we see that show-accurate My Little Pony plush dolls are in very high demand. Many complaints I hear from MLP fans is that the dolls Hasbro produces are not show-accurate, and that's why they won't buy them.
I can almost without a doubt guarantee that if Hasbro started producing show-accurate plushes, MLP fans and "Bronies" would flock to purchase them. Hasbro does not realize the high demand for show-accurate plushes and how much revenue they would gain from creating them.