Not sure what motivation you're asking about. If you mean motivation for posting links to past discussions—it's my job to help HN be as interesting as possible (see https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...), and readers seem to find those links interesting.
CXX-Qt: Safe Rust bindings for Qt - https://news.ycombinator.com/item?id=30525752 - March 2022 (108 comments)
CXX - Safe interop between Rust and C++ - https://news.ycombinator.com/item?id=26565444 - March 2021 (32 comments)
CXX – safe interop between Rust and C++ - https://news.ycombinator.com/item?id=25126280 - Nov 2020 (1 comment)
The CXX Debate - https://news.ycombinator.com/item?id=24245372 - Aug 2020 (4 comments)