Imagine it from the experts point of view. They just traveled to the arctic to drill ice cores, to bring back for analysis to learn more about the climate. They have been built climate models they worked for years on, the code is published and available to the public, you aren 100 other experts have had a go at this and come up with roughly the same results, for decades. You hop on twitter and see someone who says "I think climate change is a liberal plot" or "I think climate science is bunk" and you reply with data. The response to your data is "but I read this blog with this other data that contradicts yours!" and you go and look at the blog. It was written by a guy who is paid by the heritage foundation (who is paid by exxon and so on) who has never been to the arctic to drill ice cores, who has never built a climate model, never done any actual work except take your data and crop it in a way to sell his message. You try to explain this but communicating your expertise takes days while skeptical memes take only seconds, and all you hear back is stuff like "you are just in it for the money!" etc. Which given your moderate income, while being assaulted by guys like the Koch brothers, is pretty irritating.
So yeah, eventually, when reason keeps losing to highly funded nonsense, people stop giving a shit about being polite.
A few years ago the Koch Brothers paid climate skeptic physicist Robert Muller to do his own climate reconstruction. After finally actually 'doing the math' himself, he realized it was all true after all Of course despite this result, the Koch Brothers keep funding climate misinformation.
So, I don't really think the problem is that many people on social media reply with "your dumb" when you say you are a skeptic.
That happens in both directions, because people ont he internet have always been rude, about everything.