a project owner have the right to be dismissive about anything regarding their own project. This is why "just fork it" is both dismissive, but also power.
If you are simply asking a project owner to do somethings you wanted (often for free, i might add), then why shouldn't they be dismissive?
If you have an idea for said project that the owner is dismissive about, then you fork it - prove that the idea is good.
The dictator could be benevolent - as is most, because it's the most beneficial to be one. However, there's no rules that says they must be. They could run it with an iron fist. The contributors do so knowing this - or at least, should have known this.
Look at wordpress's fiasco, for example.
You are under the illusion that the owner is doing the project for the betterment of the community. They _might_ be, but it's not a requirement.
I personally behave as if everyone is selfish, and will be out to screw you if given the opportunity and reason. Assume the worst and plan for that; if it turns out they are nice, then all the better.
"Where can I send some cash for your hard work" is much rarer than "Here's my very complex edge use case that I need to support ASAP, I think it's quite shameful you don't support this already must not take you more than 5 minutes, come on people do it already my clients are waiting".
"It may be open source, but that doesn't mean that it is afraid of money."
Another symptom is most projects don't have an easy way to donate money to them.
The money/downloads value is so low it's basically a waste of time to set it up.
You just don't get a vote, there is no objective truth to settle disputes when it comes to someone else's work and projects. You can stop using the work or fork it, perhaps alongside other like minded users and contributors, crating a viable split.