What on earth are we comparing when discussing Nim vs. other languages, if not the language itself, in practice? Are we just discussing how good you feel about it?

My point is, this is an actual deficiency that you need to consider when evaluating Nim, that isn't just a function of the language being new. For example, Zig is another option which puts any C libraries at your fingertips, without requiring bindings. If Nim had better interop (not just relatively good, but zero effort) this would no longer be a concern and you wouldn't need all of your libraries to be in Nim.