The comment wasn't deleted and he answered it:
Nick – No one ever said Greene was left off because he only played one season. Instead, he was left out of top 5 (included in Next 5) because there were so many great running backs, ones with multiple very strong seasons. The pool was a lot deeper than it was at QB. If there were the same number of true candidates at RB as there were at QB, Greene would have made the list.
I don't agree with him, but at least he did have the stones to answer the question and not back away from it.
It was deleted but then it was put back up, as I addressed in a previous post. It's likely someone other than the author took it down and the author put it back up because he wanted to address it.