Negative Ratings has been removed from the main view, although members can still give a Poor or Good rating.
Allowing to be rated Poor is sometimes helpful to keep some members to be respectful and to help me judge when to delete a post and/or ban a member. It also allows other members to be diligent when taking advice from others if they have a lot of poor ratings. Basically it's about getting feedback from the community on member's conduct as well as the information being shared.
Unfortunately it was not being used appropriately and negative ratings were being given for the wrong reasons. This is why I have removed it from the main view since it was not accurately representing a member's reputation.
PS. As Leon pointed out, they can still be viewed under your profile. So your reputation will still be reflected and accountable from your profile page. Please use appropriately so that it can be helpful to others.