why people not givee + ratings on good discussion...??

I personally give everyone a plus response. The only grounds for me giving a negative would be if a person posted something that has nothing to do with my discussion or if they copy and pasted or their answers are short. I give a plus to everyone because, if a person took the time to read and respond they deserve it regardless of if I agree with their response or not.

I always do give a + rating to anybody who participates in my discussions appropriately and with a well-thought out answers, be it response or comments. And yes, even those responses which are just so-so yet in line with topic, I still give them a + for the time and the effort. I also sometimes give + ratings to responses of other people's discussions. Especially if they are really good. :)

I mark every single one with a +. I rarely give a - unless it was a one word. I always give "best response" to someone that I liked best.

Yes, I rate most of my respone in my disccusions. and I sometime mark minus (-) once I see those one liner, which is not relevant respone.