This is a current incident. I've moved on from all of the past ones!
Nobody is above criticism, ever. Further, just because you can be respected for one aspect of your work/life, it does not mean you can't be questioned about another.
I could equally ask why it is that the 'fanboys' accept no criticism even when it is founded in fact. Would you prefer the 'haters' to move on because it's uncomfortable to have the questions asked? Is what you mean by 'move on' actually 'ignore'?
I think that this is a trivial publicity stunt when compared to other allegations. Armstrong rose to fame out of a peleton that seemed fueled by things other than training. I don't have an opinion about the innocence, or otherwise, of Armstrong. My opinion falls into the camp outlined by Montage above.
I enjoyed watching many cyclists in that era who are now shamed. Their shame doesn't leave me feeling cheated - I enjoyed the events at the time.
I am happy to leave Armstrong in the past and look forward to battles as good as the ones in this years tour in the future in the hope that they won't be sullied by future allegations of cheating