I don't want to sound like a Prusa shill or anything, but if they see Chinese state-sponsored competition as an existential threat (and I see no reason to doubt either claim), then I imagine that, from Prusa's perspective, it's a losing proposition either way ("damned if you do, damned if you don't"): anything they develop in the open directly strengthens their competitor and doesn't elevate the playing field for the benefit of all (unpunished licenses violations) ; anything they keep to themselves turns Prusa further and further away from their ideological stance, more akin to their enemy and less relevant.