Why is Trixie So Hard to Write For?

So, I've been writing a book about Trixie lately called A Pony Anastasia where she tells about her past as part of a gypsy tribe, but not many people like it which raises the question, why is it so hard to write for Trixie? Why do people tend to shoot down stories where people like myself try to give her an interesting backstory? Granted she's not as easy to write as Derpy and Doctor Whooves and Time Ponies, but it's still fun trying to come up with a backstory for her. Let me say one thing, I don't care if you hate my story, I really don't, but you have to understand it's hard to write for a character we know little to nothing about. Anyways, at least try to enjoy the book. Thank you, bye.