They all share the same motivation, regardless of how they work or whether they exist today for Rust: providing more tools for working with partial programs.
Hi! First off, I would like to say that this idea is very interesting, and in a perfect world I would love to see it get debated to a conclusion. There's many good points being made here, for and against. That said, this conversation is no longer hashing out anything new, and I don't think it's reasonable for everyone to keep the entire thread in their head while trying to find another angle to contribute to this debate. This lead to this issue being raised to us.
I'm not keen on locking this thread at this point, but I'm also not sure how to enable this discussion to be more productive. There are points that tread on the philosophical, and with contention on them, they can only be answered by the responsible team(s). For now, I'm locking this thread, but I will reach out to the Compiler and Lang teams and ask them to decide on the next steps for this conversation. If they encourage unlocking it, we will. If nothing changes, we may have to lock the thread permanently, but I do sincerely hope that we don't have to lock the thread twice.