It would be good if the opportunity give a reason for dislike or negative reputation.

For example, I give -1 for any topic and a window appears with text "You can enter a reason". The user can then view all the texts reputation

I'm not opposed to this feature on its own.  

But can I ask, why wouldn't you just directly respond in the topic to explain whether you like or dislike? That's kind of the whole point of conversation, and you can express the gamut of your emotional responses in your reply.  

Or you can use Facebook.  ¯\_(ツ)_/¯