> My current working theory is that most people assume that "the module system" is similar to whatever one they've used in the past, then run into problems, and leads to frustration. I've talked to so many people who have totally opposite problems with it, with no real pattern to issues or expectations.

When I treated modules as Java packages or C# namespaces I hated them. Only when I realized that I can treat them as glorified C imports did they start to make sense. I still hate them, but at least I can rationalize their design now.