A qualified phrase bears markers that make it less absolute. Qualification makes the statement weaker, less provocative, but it can also bring gains in precision. Also, you get points for the reader for the modesty of your claims. If someone disagrees, you might point out that they are only disagreeing with an unqualified version of the idea, not your carefully crafted qualification of it.
On my other blog, Bemsha Swing, I'll get hammered sometimes by commenters on some statement that I haven't properly qualified. It seems absurd, ridiculous, what I'm saying.
A corollary is that you can make the most uncontroversial claim using extreme rhetoric, and people will respond to your tone, without realizing that what you're saying is completely anodyne--or use a very bland tone to smuggle across a controversial point.