Most of my bug reports have been very well accepted. The worst response I can remember is just not responding for like 3 months.

And on the other side as a maintainer, any bug report that demonstrates a clear issue (crash, hang, etc) with a reproducible setup is appreciated.

What can be really frustrating are bug reports that aren't bugs and a better understanding of the software would allow them to solve the problem. For example, there was one issue on Slic3r that was asking for a PDF output of config files. There is really no reason to do that.

That's not really help that contributes to the project, that's communication or (often in the case of usability issues) opinion that might be useful, and even if it is, it just piles on more work on the project instead of helping with that work.

Every project has accepted everything whenever I've actually tried to help with the actual work they're doing, i.e. solving a bug or submitting a pull request fixing some documentation, something that reduces their todo-list instead of adding to it.