Thanks for the interesting reply. I'm curious who "we" is that you reference several time. Do you work for an organization dealing with this problem?
To be fair, I wouldn't call this a "problem" insofar as it doesn't cause any meaningful pain apart from extra noise in the funnel. Given how poor the signal-to-noise ratio is in most hiring funnels, the impact is more or less de minimis.
I do still review every submission, at least in a cursory way, just in case the candidate has other legitimate experience and/or novel work on the github they link to.