Mods don't really set policy they enforce it, and most "Is this kind of question ontopic here?" style scope-adjusment can be done on meta.
However, here's one that bugged me:
http://programmers.stackexchange.com/questions/18120/what-is...
I thought it was a great question and set of answers. I only know it's gone because I linked it from my personal website as I was proud of my answer. Eventually somebody contacted me to say, "Hey, your site is broken." So not only did some jackass delete a popular set of questions and answers, they did it without warning and with no apparent way to recover the lost work.
That was my "Fuck you, I'm done," moment for Stack Overflow.
Which is better? I don't know. I personally haven't used either one in a while, because they don't seem to work well if you're not using a mainstream programming language. Google still wins for me here, since the right answer is very frequently on some random person's blog.
False dichotomy. How about having moderation that operates off of a flexible (and public, and non subjective) set of rules?
/r/programming sucks because of the lack of moderation. Stack* sucks because of heavy handed moderation.
(The other was how much of a pain they make it to get started if you're new - one can look at the comments here and see that those kind of shenanigans are mostly unnecessary)
When you're killing off high-quality content because it "doesn't fit the format", perhaps the format needs to change.