On the contrary, I assign a higher prior probability to movements based on sensible ideas rising to prominence, versus movements based on total nonsense.
(How many failed/successful flying saucer cults? How many failed/successful nonprofits and charities? I don't have real data, but my gut feeling says saucer cults are worse off on average.)
This means that success of a movement based on total nonsense requires a higher burden of proof in the quality of its organisation. For example good leadership, consistent message, effort in PR etc.
The factors you mention might make it easier in some respects to run a cult, but I think they do not on average outweigh the costs. If they do, we should see this reflected in the amount of functioning cults versus charities.
Quite the opposite view from the sentence you quoted!
When talking about success rates, we have to consider base rates. Are more or fewer nonsense movements founded than sensible ones?
I was invited by a stranger I met on a plane and actually went to a meeting of Raëlians (known in some LW circles as "the flying saucer cult") in 沖縄, Japan. It was right next to Claude Vorilhon's home, and he came himself for the "ceremony" (?) dressed in a theatrical space-y white uniform, complete with a Jewish-style white cap on his head. When saying his "sermon" (?) he spoke in English and his words were translated into Japanese for the benefit of those who didn't understand. And yes, it's true he talked with me briefly and then hugged me (I understand he does this with all newcomers, and it felt 100% fake to me). I then went on to eat lunch in an 居酒屋 with a group of around 15 members, who were all really friendly and pleasant people. I was actually treated to lunch by them, and afterwards someone gave me a ~20 minute ride to the town I wanted to be in, despite knowing they won't see me ever again.
If you have ever wondered how it is possible that a flying saucer cult has more members than EA, now it's time to learn something.
Note: I hope it's clear that I do not endorse creating cults, nor do I proclaim the EA community's inferiority. It hasn't even crossed my mind when I wrote the above line that any LW'er would take it as a stab they need to defend against. I'm merely pointing to the fact that we can learn from anything, whether it's good or bad, and encouraging a fresh discussion on this after I gathered some new data.
Let's do this as a Q&A session (I'm at work now so I can't write a long post).
Please ask questions in comments.