And yet, it's exactly what all the AI companies are doing. However much it costs them in server costs and good will seems to be worth less to them then the engineering time to special case the major git web UIs.

I doubt they're actually interested in the git repos.

From the shape of the traffic it just looks like a poorly implemented web crawler. By default, a crawler that does not take measures to actively avoid git hosts will get stuck there and spend days trying to exhaust the links of even a single repo.