First of all, the amish are in Karl Popper's terms, a closed society. That means that they do not tolerate critique, that they are not open to other ways of doing things and other beliefs. A while ago, I saw a documentary in which an amish born therapist described how he was rudely attacked by an amish elder for having questions about something that was not up for questioning. I cherish the open aspect of our culture, as imperfect as it is (and open to improvement). Perhaps the amish are not totally closed, but change takes much longer in amish culture. Since not all change is for the better, perhaps that is not such a bad thing.
Some leftists will point out that our society may not be that much more open than the amish. Leftist critiques of our culture have pointed out that the kind of change that happens in our culture is superficial or negative, and that dissent can only go so far. Fashion and technology change, but the mode of production, consumption and ownership of goods has not changed in a while. One can critique all sorts of things about our economic system, but at the end of the day one is forced to participate in it or live in demoralizing and humiliating conditions. Of course it is not a black or white proposition and a minimal amount of participation is possible, without having to live in dire conditions. Nevertheless I think that the amount of influence most people have on their external circumstances is small, and the open aspect of our culture is not that helpful to change that (people who have been through state communism and fascism should read Erich Fromm's Escape From Freedom before they disagree). Where the open aspect of our society makes more of a difference is to people's internal psychological states.
Second, it seems to me that the amish are rather subdued and tame. They have eliminated the extremes of human emotions in favor of a calm middle ground. They do not suffer from depression, but neither do they have ecstasy.
Third, the amish are not strictly a local economy, even for basic needs. They do trade with the global economy, sometimes pretending that they are selling their own products when it might be manufactured partially in China (I saw an advertizement for an amish made wood stove and when researching it more closely, the stove was made in China, and only a stove addition was amish made). They employ power tools and electricity from the global economy in their workshops.
Another critique of amish culture is their blinders to the effects of uncontrolled reproduction. They are starting to feel the effects of a finite land base as more and more young men have to take jobs in “english” factories instead of farming. Perhaps the meme of uncontrolled reproduction is somehow linked to the meme of a closed society. If the amish meme network were able to propagate itself better memetically, perhaps it would not need to propagate itself as much genetically. Perhaps unbridled reproduction is a parasitic meme in humans, increasing it's own fitness and that of the population in the short run, but hurting itself and the population in the long run.
Back to the commendable aspects of amish culture mentioned at the beginning of this article. There are two I want to discuss:
1. Intimate community and
2. Long-term community sustainability.
Is it possible that one of the necessary ingredients for both of these desirable aspects is a closed society? Having a foundation of values (usually religious) certainly seems to help form community intimacy, and prevent the ideological conflicts that lead to people leaving and communities breaking apart. I think this is the same issue in committed couple relationships (usually marriage) and possibly in larger groups of people such as nation states. I believe, but do not have empirical evidence, that though a non-negotiable foundation can be helpful for intimacy and sustainability, that love and commitment could form an equally strong foundation. And that a foundational belief could be the belief in openness and ability to question everything, in a loving, or at least civil way, with a desire to improve, not just to critique.