I think it is very rude to refer to people who have concerns or who are not totally satisfied as "Negative Nellies". Name calling, labeling or stereotyping people can be considered negative as well. Freedom of speech is important and everyone has the right to voice their opinion. If you don't want to read something you define as negative, it's so easy to just click away from it. And of course, I think it's perfectly fine that you voice your opinion as well but I think it is poor message board etiquette to derogatorily label people.