Maybe I was not clear -- I am not arguing for proprietary datasets. Validation on publicly available data is a key component in comparisons, assessments, etc.

Maybe I was not clear -- I am not arguing for proprietary datasets. Validation on publicly available data is a key component in comparisons, assessments, etc. However, there is a whole bestiary of open source licenses that span the spectrum of "use any way you want" to much more restrictive. But they were mostly thought through for software and data is different; what may prevent proprietary abuse in software may not have any teeth for data.