The truth is that people are shit at using a computer (https://www.nngroup.com/articles/computer-skill-levels/). At some point we need to draw the obvious conclusion from that: users capable of useful contribution to a project are a significant minority compared to the number of users who need or wish to use that software. How many people develop software? About 5%. How many people need to use software? 95% or more? Point being, no matter how important or unimportant your software is, you are guaranteed to have a user base predominantly incapable of contributing to the project.

This is why the constant responses of, "Patches welcome," or similar in response to user complaints is so hostile to users. It's saying to users, "This application is only for experts," which is likely to only appeal to experts. Since experts are so rare, that doesn't seem like a particularly inspiring response. You're just driving users away from your project.

Yes, anybody can contribute to an open source project. No, not everybody is capable of doing so meaningfully. Yes, anybody can recognize a bad design or bug. No, not everybody is capable of recognizing a good or correct design or fixing a bug. If Linux is to ever become an operating system for the desktop, we must accept that the majority of users are not going to be developers, and a user cannot be expected to become a developer just because they want to use a computer. It is no longer 1975.

The only exception to the above is if your project has a user base entirely devoted to programmers. That's precisely why those projects get so much development time.