I read so often about hamsters not eating those pellets and I must admit that Ebony and Hazel usually leave them too, (well Hazel leaves everything so that doesn't really count LOL), but they are the first thing Willow goes for, she just loves them
I do agree with Cyoher, they are in the mix for a reason but hamsters are all different and they can't all like everything can they so it stands to reason they will eat what they like best first and leave what they don't like
Personally I don't think it's a problem if they leave the odd bits out