The thing is user's want a solution: if a user is reporting a bug then already two things are true: (1) they're experiencing it and it's blocking them from usin

The thing is user's want a solution: if a user is reporting a bug then already two things are true: (1) they're experiencing it and it's blocking them from using the software and (2) it's significant enough to their process they didn't just install something else. So "user reporting a bug" is already an unusually highly motivated individual compared to the alternatives. Which leads to (3) they were trying to use the software right then, and a response from package maintainers of "this is an upstream bug" doesn't solve the problem, and in fact barely implies that a solution might be being requested from upstream. Which also leads to (4): the most common immediate resolution anyone is going to present that user is "use the latest version / master / whatever". Which means the user is already going to make the transition to "now I'm a direct upstream user" (and equally the high probability the bug might still exist in upstream anyway).