Because they tend to take extreme or simplistic positions in opposition to any sort of nuanced or interpretive view of the law.

In this case it's "Hey, it's Oracle's code, end of story."

Is intellectual surprise caused by anything other than bias?

I noticed this when I started rereading the dissent with a s/Oracle/Sun Microsystems/g. I felt a bit more swayed when I started to recollect all my fond Sun memories: blogs, hobbyist customer experience, etc. and stopped thinking about my glowing hatred of Oracle.

The dissent does seem nuanced to me even though I am quick to dismiss it based on the premise and my superior technical knowledge and maybe a bit of my own biases that I can't quite completely ignore.