Completely Unemotional

The Compromise of 1850 wasn't just a political, legislative document, but the whole point of its existence was to try and relieve tension between groups of people who had very different opinions. You're not going to do that very well if you use language to express some kind of emotional response to any of the laws being laid out.

Take the Fugitive Slave Act, the most controversial and in the end, the most emotionally charged part of the Compromise. It describes how the courts, for instance, "shall from time to time enlarge the number of commissioners, with a view to afford reasonable facilities to reclaim fugitives from labor, and to the prompt discharge of the duties imposed by this act." (Fugitive Slave Act.Section 3.1)

That's saying that the courts can increase the number of people hunting down slaves if they feel it's necessary. Of course, slaves become "fugitives from labor" and all the means of hunting them down are referred to as "reasonable facilities." Language throughout the Compromise is like this, avoiding embellishment, emotional adjectives, and anything really that could be construed as favoring one side or the other. Kind of like calling torture "enhanced interrogation."

Neutral tone like this would be essential for the purpose of the Compromise. If after all that debating, the final results looked like they favored the North or the South, who knows how the other side would have reacted.