I agree that the rating system is not really necessary and a little silly.
There was also that thread a few months ago (which I won't link to because it
should stay dead) in which someone intentionally abused the system with
multiple down-votes from the same IP address to hide certain comments. If
this happened frequently I would agree that the voting system should go, but
I have only seen it happen once and a moderator addressed it promptly.
A post is only hidden if multiple people down-vote it, so apart from
situations like the one I alluded to it is unlikely that a comment will be
hidden without good reason. All of the comments I can remember being "hidden"
(displaying them is optional with JS enabled, and they are always displayed
with JS disable) have violated the community guidelines. Even if a post does
get hidden without good cause, others can quickly cancel out the down-votes
with up-votes.
The alternatives would be (1) have moderators delete the posts or (2) change
the community guidelines. I think that indicating that a post is
inappropriate without censoring it is a better solution.
