Earlier quoted context omitted.
Why is the dataset required for it to be open source? If I self host a project that is open sourced rather than paying for a hosted version, like Sentry.io for example, I don't expect data to come along with the code. Licensing rights are always up for debate in open source, but I wouldn't expect more than the code to be available and reviewable for anything needed to build and run the project. In the case of an LLM…
The sticking point is you can’t build the model. To be able to build the model from scratch you need methodology and a complete description of the data set. They only give you a blob of data you can run.
DOOM-the-engine is open source (https://github.com/id-Software/DOOM), even though DOOM-the-asset-and-scenario-data is not. While you need a copy of DOOM-the-asset-and-scenario-data to "use DOOM to run DOOM", you are free to build other games using DOOM-the-engine.