I have seen you advise people on how to add data derived (literally, in a sense that fully falls under copyright in all jurisdictions) from a third party source to osm.
I have no feelings against that. After all, it actually only affects downstream consumers, so I do not share your fear of OSM going down from such mappings. Yet, from my reading of legalese, resulting data though cannot be relicensed under ODbL and therefore should not be in the data.
More info here The CC-0 Advantage: How the EU Open Data Directive Can Benefit from Simplified Licensing for Geodata | OpenStreetMap Blog