[Fomite]

Because there are data use agreements for health data with personal identifiers, and the vast majority of them aren't going to accept "We're keeping a copy on a private Github repo".

Nor, to be blunt, should they.

My particular simulation work is rather interested both in individual runs (and indeed, individuals within those runs) as well as summarization.

Beyond that, what use is there to putting just the "summary" data online, when the underlying data made that still exists as "you're just going to have to trust me". Being able to replicate my figure code doesn't get people very far.