It was actually turned off by default, I turned it on to see how it works. 2.5 seconds later I got my first -1 !!
I will see if there is a way to disable the negatives. I think it's much better to have just the appreciation part, if you dislike should be like no vote.
Someone asks what is the lowest? At this point I think can be any value.. like -999999.
The delay can be configured, was 1 hour before, I raised it to 24 hours. Open to discussions.