The question, Do the Amish have a lower rate of autism? is looking like a road accident.
This question is to explain what happened, and to invite suggestions on how to fix it.
Let's work our way through it.
The initial version simply asked whether autism was low among the Amish, and whether that was because of low vaccination rates.
Now, the question of whether MMR vaccines cause autism has been addressed already on Skeptics.SE, and then again when new documents came to light, but this was a new question. However, it had no notability.
The logical flaws in this article are numerous and it contains a number of JAQing off hedges. (i.e. that we should spend more effort investigating some journalist's whimsical questions.)
Worse, it doesn't explicitly state that the Amish are (a) lower in autism or (b) vaccine-deniers. It does quote one doctor as saying that he hasn't seen autism.
At this point, an answer was given by @jamesqf that (a) argued autism wasn't linked to vaccines (citing a meta-study) and (b) supposed, without any evidence, that the Amish community might be more accepting of children on the Autism spectrum without a diagnosis.
That answer was downvoted, flagged and received upvoted negative comments, before I saw it. I deleted it on the grounds that it wasn't an answer.
The reference did NOT address the issue of the Amish at all. Without evidence, the supposition that the Amish are more tolerant of mental health issues is little more than prejudice, and didn't add to the answer.
Further, it is inappropriate to respond to a claim that evidence exists with a generic "There is no evidence." If there is a lower level of autism amongst the Amish community and they have a lower vaccination rate and there are no confounding factors, including lower diagnosis specificity in their health regimes, then that would need to be included in the next version of the meta-analysis, not ignored out of hand.
(On the other hand, if you wanted to argue that such a study should be low priority, should not be sponsored by the public purse, and that the subjects of such a study should be informed before signing up that the study is highly unlikely to advance scientific knowledge, then that link would be useful.)
The answerer complained in a comment that the answer was still valid. I hope this explains my reasoning.
Version 3 (disclosure: edited by me) improved it slightly but didn't really address the key flaws. The question was now focussed on an article that argued in circles.
Version 4 just added a tag,
The second answer by @RobWatts doesn't answer the question either.
It points out the nonsense article makes some errors: the Amish do vaccinate, that the quoted doctor is probably exaggerating about his exposure to the Amish and that the authors peers criticise him.
So, now we have an answer eviscerating the Olmsted article... that wasn't part of the OP's question. We, as a community, added an article for notability, focussed the question on that answer, and then shredded that article as nonsense, leaving the original question from the OP unanswered.
I've closed the whole sorry mess. I hope the OP can come back and clarify where he heard the claim - was it from Olmsted?
Olmsted certainly makes claims that we can investigate (and, it seems) rip apart, but until it is clear that is the target, we should hold off.
If it is the target, we should be more explicit which of his claims are the ones we should investigate.