Evoking emotions is the role of art, not data visualization.
Beyond the potential emotional power of a well-chosen and executed visualization, there's also a decent bit of research about the ability to influence mood via color choice. Color choice when visualizing data can make a huge difference in its effectiveness due to this emotional effect.
Charts should be about hard data, not rhetoric.
And like I wrote about, you can have very precise charts that can be extraordinarily manipulative.
The whole "charts should be about hard data" thing always sounds nice, until you realize that every visualization is an abstraction and brings in some human bias. You are always picking the scales, whether or not to use color, how to aggregate the data, etc. There is no such thing as a neutral chart.
Also... there are data visualizations outside of science. Of course science should be more precise than something like data art.