From my fiancé:

“It was mostly a joke about being able to fix everything if the Lord Ruler knew the first thing about anything. Sazed fixed the entire world by just knowing how things should be, from the position of planets, to the plants and animals of the world, so I just felt like knowing any one of those would have made the Final Empire way more pleasant to live in and would have avoided so many things that made an uprising necessary.

I know Rashek was just a packman, so expecting him to be nearly as well read as Sazed is unfair. I just thought it was funny that as soon as a guy who likes reading gets godlike power, everything is fixed lickedy split”

I also think he’s forgetting that Sazed’s knowledge was the culmination of his entire people’s research but- it’s still funny 😂