There's trolling, and then there is the negativity which comes from utter weariness with things. You spend 5 years on the mailing list, trying to help all the newbies, but it just never gets any better. Every week there's a new guy who didn't read the archives, who never even bothered to look at the documentation or the FAQ, or who thinks he knows (after a 10 minute reading of the Wikipedia article) that he knows exactly what's "wrong" with your project and that his ideas will solve everything. You spend 5 years politely pointing them to the right place, or gently explaining the problems with what they're proposing, but nobody ever learns. Then you just start ignoring them, because you've run out of politeness--this is how we get 3 year old bug reports with 20 "me too!" comments and a single "Won't fix. Closed" from the developer. But all the other people have started ignoring them too, except the very-recently-noobs. Who don't know any answers, but will happily post all sorts of misinformation and noise. So you start to answer questions like "How to download iso plz?" with "Look at the fucking front page of the website", instead of the old "Here's a link, and you'll need bunzip2 installed to unpack the file". You've spent years trying to be nice and polite but it never seems to help--you just get more entitled idiots asking the same crap, so maybe it's time to try being nasty.
In the end, of course, it doesn't help, but it sure feels good to get that out. I'm working on it, because it's not good for the community, but it's hard to avoid sometimes.
It sounds like you are describing burnout. Normally being easily irritated by expected behavior means that one is tired,
Beginners are going to ask the same questions. Some of them will ask for help rather than read the documentation because they learn better through social interactions than through reading. Some will propose ideas that seem good to them but the community has already found them flawed.
When one reaches the point of being easily irritated by known normal behavior, it is time to get out of there to prevent negative behavior. Take some time off from the mailing list. It sounds like you have at least spent 5 years. It could be longer. Take a break. Rest. Ask others in the community to help out beginners.
So, when you become the equivalent of a weathered, crotchety old man in the Open Source community, in IRC, at meetups, or anywhere else... kindly fuck off.
Sorry to be so blunt, but that's the point, here. It's fine not to want to help annoying beginner #5,000,000, but it doesn't require being an ass to the community, at large. Just keep your mouth shut, unless you have something nice or helpful to say, please.
In the end, of course, it doesn't help, but it sure feels good to get that out. I'm working on it, because it's not good for the community, but it's hard to avoid sometimes.