You're probably right. All I can say is, when you get 100-200 emails a day, every day (it doesn't stop), it's hard. That's not an excuse nor a justification. it's just a statement, an explanation at best.
Also understand that your expectation of a maintainer's response, however small or trivial, is at direct odds with the time they spend working at their day job, or spending time with their family, or relaxing. That's not to say open source maintainers don't enjoy building and maintaining open source projects. Most do (including me). It's just the recognition that maintaining open source projects comes at the expense of other things which they also enjoy.
In the same way that I believe you're justified in thinking a maintainer's non-response is rude, I believe a maintainer would be justified in thinking your expectation of them is also rude.
