Inline documentation and charting (which for data tasks is a honking huge deal). It's literate programming with an actual use-case. Very into this idea.
You'd be surprised. It's certainly not _all_ of what people use bash for, but there are a lot of sketchy ETL (and sampling, and small-scale analytics) jobs out there held together with bash and awk and hopes and dreams, and replacing those with something like this is a substantial win.
