He's not referring to debates as being the problem. Quite the contrary: "In the civil group, those who initially did or did not support the technology — whom we identified with preliminary survey questions — continued to feel the same way after reading the comments."

Civility does not mean blindly agreeing. It means just that: acting civil.

However, what he does argue against is rudeness and insults. Essentially, not debating, but slinging mud.

"Simply including an ad hominem attack in a reader comment was enough to make study participants think the downside of the reported technology was greater than they’d previously thought."

Simply put, you can act civil even if you disagree. This does provide value. However, when that civility is removed, the results are polarizing.

If you can't see the benefits of civil debate, you are an idiot.