The comment is discussing Nietzsche's contempt for moral conviction, but more telling is the thoughtful "reprimand" coming from Mary Anne Evans:
But we certainly do find Nietzsche sneering in places, and in some of those places, that sneering is directed at moral conviction itself. When in the midst of a tirade against nearly anyone and everyone ever to put pen to paper, Nietzsche heaped scorn upon “G. Eliot” and her fellow “English flat-heads.” Eliot – whose actual name was Mary Anne Evans – had long since rejected theistic belief, but she held fast to a sense of moral duty that she regarded as “peremptory and absolute” (Myers 1881, p. 62). Morality, she thought, simply did not require a religious foundation. Indeed, the religious impulse dilutes the moral, as thoughts of another world distract from the duties of the present, and hope of an eternal reward reduces moral motivation to a form of egoism. Instead, hers was a “Religion of Humanity,” involving “the expansion of the sense of human fellowship into an impulse strong enough to compel us to live for others, even though it be beneath the on-coming shadow of an endless night” (Myers 1881, p. 61).
Unfortunately I don't have access to the entire article and can not give a final answer on why she might be right or wrong according to the writer. A sure hint would be Nietzsche's position on morality in general - in my mind Nietzsche does give a complete argument why morality has no meaning without God.
But I would not like to discuss why anyone (like Nietzsche or Theists) would think Mary Anne Evans is wrong. I would like to ask why there are practical or intuitive credibility in her assertion that "...the religious impulse dilutes the moral..." Is it true that Christians are preoccupied with heaven to the extent that they neglect their moral duties in this world?