Also, I'd argue that Tableau doesn't require any particular expertise beyond what is required for Excel. Though Tableau isn't my preferred tool, I've seen great results come from total novices. It has the side benefit of sneakily training people to "think beyond the canned" and to develop novel visualizations that may better get to the heart of the relationships present in the data.

I get it that ggplot2 requires some minimal coding ability, however I've also seen good (i.e. superior to stock excel) results come out of never-before-coded grad students in an only nominally quantitative discipline. Certainly the business people who power our economy and command great sums of wealth are capable of such modest feats?