Thanks for the mention! That's an accurate way of describing it. I updated the home page with the one page description: Oil is our upgrade path from bash to a better language and runtime.
The ability to run existing POSIX and bash scripts is the biggest difference between Oil and other new shells (something I'm often asked). Unfortunately that's also why it's such a long implementation effort. But in reading the comments here, I still think that was the right choice.
----
FWIW Oil's approach to structured data is to use interchange formats over pipes. You can already pipe JSON, HTML, and CSV/TSV over pipes, and people do. There are many command line toolkits that do this.
https://github.com/oilshell/oil/wiki/Structured-Data-in-Oil
However the shell is also missing few things which would help that approach, so I'd like to build some native understanding of those formats into it, without requiring any special "plugin interface". Plugins are simply processes in Oil.
For example, Oil already has a QSN "Quoted String Notation" to properly escape byte strings like filenames (this happens to be the format of Rust string literals, which are similar to C and JSON string literals). So you don't have to do parsing and splitting.
The approach to tables will likely be built on QSN in TSV or QSV. And then you can enhance "npm list" and "dpkg" just to print that to stdout, without having to integrate into any special "plugin system". It just works with normal Unix processes and the kernel.
https://github.com/oilshell/oil/wiki/TSV2-Proposal (not implemented)
Update: I just wrote a draft of "Why Use Oil?"
http://www.oilshell.org/why.html
Let me know what you think! (feedback link in the article)