In the end, an open source project is just a bunch of humans, and where there are humans there isn't always harmony. This is a social problem, it is not specific to open source, and there is nothing particular about open source that would help avoid this.
However, open source has an escape hatch: any open source license allows you to fork the project. You can do your own thing, without having to engage with the current maintainers. The two projects can still use each other's patches as long as they stay under compatible licenses.
If you do a better job at maintainership than the current maintainers (and good maintainership involves social aspects such as the tone used to respond to bug reports), then the community may eventually migrate over to your fork. Or may not. Part of the beauty of open source is that the code and the community cannot be shackled to a particular maintainer or vendor.
Such forks (either a fork of the code that won over the community, or the community moving to a similar but separate project) have happened multiple times over the history of open source.
An older example might be the XFree86 server that was developed by a Core Team. After some drama most developers eventually moved to the X.org fork that is nowadays used by most Linux distros.
A more recent example is the Node.js → io.js fork in 2014 over a disagreement in project governance. However, a few months later the two projects reunited under the governance of a neutral foundation.
Unfortunately, maintainership requires a ton of effort.
If you really want to go that route, you should check a couple of things first:
- Is the project really under an open source license? OSI-approved licenses should be fine.
- Is the project name encumbered by trademarks? For example, you cannot distribute your own version of “Java” or “Firefox” without changing the name and branding.
- Does the license include a requirement to change the name? The Artistic License and the Open Font License come to mind.
- As a practical consideration: is the original maintainer particularly litigious? Just because you have a right to fork the code doesn't mean they will accept this. They could e.g. hit a GitHub repo with a DMCA notice which will force it to be taken down at least temporarily.
Maintaining a good fork isn't just a lot of effort, it will also be perceived as as quite hostile move. This will likely sever your relationship to the original maintainers beyond repair. But if you don't have a workable relationship to begin with, nothing is lost.