Derision of stupidity is probably one of the worst characteristics of hacker culture, because “stupidity” tends to be shorthand for “disagreement with my point of view”.
I have trouble making a cogent argument around the derision of stupidity because derision should be self-evidently bad. It should automatically file under “why would I want to do this to my own personality”. Derision and bullying are indistinguishable from each other, and the thought that a group as oft-socially-maligned as hackers (at least until the last 6 years or so) defaults to derision seems more a sign of imitating things we were subjected to than reasoned thought.
“If you go up to a group of people who are used to doing things according to procedure X and you blithely ignore it, you really should not be surprised when your efforts are met with derision at best and hostility at worst.”
What does blithely ignore mean? Say this is the first open source project I've ever contributed to, so I don't know what the norms are in terms of where to even look for guidelines. Or I contributed 30 minutes of my time because that's all I had, and I devoted them to this. Or I'm learning to program, and I chose to try to help your project.
I will posit that anyone who is trying to contribute to your project is doing you a kindness. They may be doing it in a poor way, and you are within your rights to point that out. But how you point it out is what we're talking about. You an politely point out that the project doesn't accept pull requests. You can politely point out that tickets can't be opened until there's been a discussion on the mailing list. Etc. You can even be curt.
Derision is not curtness. It is not impatience. It is explicit, intentional putting-down of someone because they aren't as good at something as you are or think they should be. And it is a poison. Unfortunately, if you take it frequently enough, it becomes habit. It becomes second nature. And you stop noticing it's poisonous. And so, unfortunately, it is an oft-enjoyed poison in intellectual circles. It doesn't help anything. It doesn't help you understand the world or other people. It doesn't really save you that much time. It simply makes you feel better about yourself.