Pretty much this. Also, the advice being given might more accurately be "you don't do X, because you obviously don't know how to judge the context and details and are therefore very likely to get it wrong". Except, if someone actually says that, the person it's being said to is liable to try to rope them into explaining the context-and-details thing, which 1) is very complicated, to the point where explaining it is a major project and 2) most people can't articulate, so that's awkward if it happens. Also, it's often true that once a person does learn how to judge the context and details properly (on their own, generally speaking, by observation and reading many things on the topic), they will then be able to see what they were doing wrong before and how to avoid that mistake, and conclude that they can try again regardless of previous advice.
Most of what I just said isn't relevant to meetup groups, though; bogus' angle is much more relevant there.
One of the lessons highlighted in the thread "Less Wrong NYC: Case Study of a Successful Rationalist Chapter" is Gender ratio matters.
There have recently been a number of articles addressing one social skills issue that might be affecting this, from the perspective of a geeky/sciencefiction community with similar attributes to LessWrong, and I want to link to these, not just so the people potentially causing problems get to read them, but also so everyone else knows the resource is there and has a name for the problem, which may facilitate wider discussion and make it easier for others to know when to point towards the resources those who would benefit by them.
However before I do, in the light of RedRobot's comment in the "Of Gender and Rationality" thread, I'd like to echo a sentiment from one of the articles, that people exhibiting this behaviour may be of any gender and may victimise upon any gender. And so, while it may be correlated with a particular gender, it is the behaviour that should be focused upon, and turning this thread into bashing of one gender (or defensiveness against perceived bashing) would be unhelpful.
Ok, disclaimers out of the way, here are the links:
Some of those raise deeper issues about rape culture and audience as enabler, but the TLDR summary is:
EDITED TO ADD:
Despite the way some of the links are framed as being addressed to creepers, this post is aimed at least as much at the community as a whole, intended to trigger a discussion on how the community should best go about handling such a problem once identified, with the TLDR being "set of restraints to place on someone who is burning the commons", rather that a complete description that guarantees that anyone who doesn't meet it isn't creepy. (Thank you to jsteinhardt for clearly verbalising the misinterpretation - for discussion see his reply to this post)