I agree with OP - the weights are more akin to the binary output from a compiler. You can't see how it works, how it was made, you can't freely manipulate with it, improve it, extend it etc. It's like having a binary of a program. The source code for the model was the training data. The compiler is the tooling that can train a module based on a given set of training data. For me it is not critical for an open source model that it is ONLY distributed in source code form. It is fine that you can also download just the weights. But it should be possible to reproduce the weights - either there should be a tar.gz ball with all the training data, or there needs to be a description/scripts of how one could obtain the training data. It must be reproducible for someone willing to invest the time, compute into it even if 99.999% use only the binary. This is completely analogous to what is normally understood by open source.