Wrong tool for the job.
D3 fills the void between "just send my data to a bar chart" and "I need some charts, maybe I'll use raw JS to manipulate SVG's". You're probably in the former camp.
`The last thing I did was an area graph that you could click and drag one of the edges and it would update the numbers in the legend as you did it.`
That doesn't sound like "just send my data to a bar chart" to me.
The examples do "cubic" instead of just "connecting the dots" but luckily it can be turned off:
http://www.chartjs.org/samples/latest/charts/line/interpolat...