I like Rails and ActiveRecord just fine, so I don't meant to bag on it. But they do talk a lot about "magic" in the Rails community. Check it: http://www.google.com/search?q=rails+magic
If this blog entry is just a restatement of "there is no silver bullet," then I agree. However, you can't blame the tools or their authors for what some people in the user community claim. The root of the problem is clearly a combination of lack of understanding and laziness.