The study found that incivility polarized opinion. For example, someone with a positive view of nanotechnology would have their perception of potential risk decrease in the face of uncivil comments.
To me, this suggests that there is a trade-off. Pushing your beliefs in a manner that some may consider rude is likely to amplify the support of those who agree with you, at the cost of strengthening the beliefs of those who oppose you. For a site such as this, that may make it the correct strategy to be more rude on issues where there is consensus, while being calmer on issues that divide the community.