Honestly, from what I've seen many people don't see the issue with this. "The code is public anyway, so what difference does it make?"
I'm starting to see the downsides of that viewpoint now, though[0]. If GitHub, and by extension Microsoft, technically 'own' the code (licensing, etc.) then they have free reign over it, leading to things like Copilot and Intellicode.
[0]: https://github.com/MicrosoftDocs/intellicode/issues/201