On piracy, HN users defend Sci-Hub to protest against the academic publishing industry, which involves large corporations such as Elsevier charging publishing and subscription fees that are much more than the value that these corporations bring to the actual research, review, and publication. Academics need to publish in order to survive, and they individually do not have enough power to subvert the existing academic publishing system. Since academics do not receive royalties, Sci-Hub enables academics to pay less into the same system that exploits them for profit. By supporting Sci-Hub, HN users take a populist stance by supporting individuals against the system.
The situation with Microsoft and Copilot is the exact opposite. Here, Microsoft is misusing its acquisition of GitHub to repackage the work of individual free and open source contributors into a proprietary product in violation of the authors' software licenses. These licenses do not even require Microsoft to pay. They only require attribution and redistribution under a compatible license. Supporting Microsoft's misuse of GitHub is an anti-populist stance that puts the interests of the corporation over the interests of the individuals.