To what extent are changes to posts of others OK? When does the meaning change?

Question

Because it came up again in some of the comments of a particular question here once of at all:
To what extent are changes to posts of others OK?

Background: don_crissti hijacked someone else's answer to add a different solution (after discussing with me similar solutions in the comments to my post but that's not important here), to which I objected. I pointed to a [meta-se] post which said that edits should not change the meaning/intent of questions/answers and in my the opinion a different solution would have been such a no-no change. (IMHO, this is even the case if the different approach would have led to exactly the same result.)

From what I gather (mostly from discussions that got deleted in the meantime) don's position seems to be (@don: please correct me if I'm wrong) that:

1. [unix-se] is not [so]
2. The content here is a collaborative effort.
3. These sort of changes are OK and this is the majority opinion.

Because of point 1 and 3 I'm creating this thread here, and concerning point 2 I would argue that there is a difference between posts marked as community wiki (which is not the default) and those that are not for a reason. So it's not all wiki in that sense.

Please note that this thread here is not meant to be about those specific edits mentioned in the background section but to come up with a somewhat clear consensus rule on what is and what isn't OK for editing on [unix-se]. Specific examples are OK though (but obviously no finger pointing please).

Answer 1

I had a similar discussion on Meta SO some time ago. Quite frankly:

I consider the SO position dumb.

On both Ask Ubuntu and Unix & Linux (I find both these sites are very similar when it comes to editing), several answers have been edited (even extensively) by multiple editors over time. If I see an edit that simplifies commands in a post, or provides a combined version, or updates it, or fixes some problem in it, I'd happily accept. And so would most users I know on either site. I have had contributions to my own posts, suggested and directly edited.

Specific instances (from trawling the list of top-voted questions):

1. https://unix.stackexchange.com/posts/1292/revisions
2. https://unix.stackexchange.com/posts/10650/revisions
3. https://unix.stackexchange.com/posts/3572/revisions
4. https://unix.stackexchange.com/posts/25378/revisions

(And I bet you could find many, many more.)

The only time I reject such a change would be when the new method is so different from the original that it has nothing in common, and should probably be recognised as a different answer.

As for community wikis, I rarely see those created these days in AU or U&L - and usually then the user specifically intends to gather multiple answers together. For me, community wikis have pretty much lost all meaning (beyond the underhanded protection from downvotes that I have seen some people misuse).