I disagree. Voting down should be used judiciously but I think it's still important that it be used. I think the system already has enough built in protections in this regard. Down votes are costly to the voter (-1 rep) and have only a small effect on the rep of the target (-2 rep).
Not to pick on the author of the given example, but take a look at his user pagehis user page. He's posted 1 question and 1 answer. His answer has 0 net votes and his question has -5 net down votes. Yet he has, just now, 47 total rep (which, incidentally, is enough to allow him to vote answers up or down, per his complaint/question). Given this I think it's a bit ridiculous to say that people voting his question down represents "being hard on him".