We are against. We launch our attack against our comrades in arms instead of at the enemy. The antidote to negativity is to start doing something yourself. Refuse to tear down what someone else is working to build. When I speak of criticism in this context, I do not refer to the art of discernment with the end of evaluating quality and usefulness.
Criticism here denotes passing of unfavourable judgments, censure or disapproval.
It is different from negativity in that it is usually focussed on other persons. We see what they are doing, make assumptions about their character and then criticize them. Criticism, to be truly satisfying to the critic, requires an audience. Put two critical people together and they feed off each other. Soon, some poor soul who doesn't meet their expectations is torn to pieces.