I found this article on a British music blog, and I think it hits the nail on the head. It's about how Hilary chooses terrible singles.
Zappin' it to ya...
There's nothing like reading a blog that is cutting edge and up to date with its music recommendations. And this is nothing like that blog ;) But then again, Hilary Duff is hardly cutting edge and up to date, is she? And for some inexplicable reason she has just released her single Fly here - which barely flew into the British charts at number twenty. Snarf! And you know why? Hilary Duff chooses the worst singles from her albums this side of Liberty X.
I like the Duff. Sort of. Its not like i can't get enough of that wonderful Duff but she is named after a British slang expression for being pregnant, so you gotta like her a bit for that :) Her single choices are horrific though. Oh sure we all tolerated the chirpyness of Why Not and So Yesterday, but then she started releasing dross like Come Clean, Fly and Wake Up. If you search deep into her albums there are much choicer and chirpier pop gems which I think would have been much bigger hits for her. We already have Kelly, Avril, Lindsay et al sounding dead miserable about their lives. When she wants to, Hilary puts a bit of kick back into pop and actually manages to sound like she is enjoying herself. The Math and Haters are two prime examples of this and are presented here for your listening, erm, "pleasure"! Now don't get me started on having a greatest hits collection after two albums...
http://thezapping.blogspot.com/2006/03/hilary-duff-least-wanted.html