What you are describing is a perfectly typical (and expected) behavior for a user of a commercially-licensed library/server software.
Many developers/admins use both FOSS and COTS, and feel the same low-effort interaction with upstream is okay in both cases. It's possible to educate a small number of your users (and to a some extent, you should try - for example your post here is a small step in that direction!), but that work is even lower-reward than answering those half-baked reports.
To deal with low-effort, good-faith user reports, in COTS scenario, you'd hire a support/TAC person (a team, eventually). For a popular/accessible FOSS project, it is possible to have something similar on a volunteer basis:
- set up IRC channel/slack/forum/mailing list for that;
- display a prominent banner asking to "please try support forum first" on your bug submission page;
- encourage people who want to contribute, but are not quite acing your codebase (yet), to hang around in the forum, help others.
For very popular community projects, you can indeed solve the problems by throwing some manpower at it.
However, there's this uncanny valley of somewhat popular, mostly solo maintainer projects where you get a steady stream of tickets (say one or two a week) yet there's no community to speak of, so everything falls onto you. It gets pretty annoying when you have a couple of these uncanny valley projects.
Many developers/admins use both FOSS and COTS, and feel the same low-effort interaction with upstream is okay in both cases. It's possible to educate a small number of your users (and to a some extent, you should try - for example your post here is a small step in that direction!), but that work is even lower-reward than answering those half-baked reports.
To deal with low-effort, good-faith user reports, in COTS scenario, you'd hire a support/TAC person (a team, eventually). For a popular/accessible FOSS project, it is possible to have something similar on a volunteer basis:
- set up IRC channel/slack/forum/mailing list for that;
- display a prominent banner asking to "please try support forum first" on your bug submission page;
- encourage people who want to contribute, but are not quite acing your codebase (yet), to hang around in the forum, help others.