This is how Stack Overflow is designed to work. One single user is not supposed to be able to edit a top answer and change it into a different answer.
The Stack Overflow Way™ is to post a new answer that tells the correct answer and why the other answer is wrong. Then the community has two separate answers and they can vote on which one is more correct.
Confusing? Yes. Arcane? Yes. Did the system fail in this specific circumstance? Absolutely yes.
But they can't just let people edit highly voted answers into fundamentally different answers. That's why your edit was not approved.
The intended outcome here is that you post your own answer, and leave a comment on the most upvoted one summarising your concern with it.
And that readers don't just pick the most upvoted one, (even though it's obviously the site's design that they should be able to do that).
The answers have a sort order, controllable by tabs below and to the right of the question. These go to the same page with a GET arg to change the order. The trick is that these are sticky - browsing to one saves it as your preference. So if you post a comment to a question and include that arg, it'll switch the whole site for whoever clicks it, without telling them.
One of the options is "newest first".
Last I contributed anything on there I was being told by a single poster that my question was 'wrong', and descending into an argument - and started throwing SO convention at me. I just deleted the question. There's a sociopathic nature about those looking for ratings and authority that's totally at odds with simple sharing of knowledge and learning.
I appreciate SO and use it many times a year. I remember the world before SO (experts exchange was very bad), so I’m happy it exists. And it’s obviously getting along without my comments and moderation.
I always wished it would pair well with something like HN so the reputation effect from a daily activity would carry over to an infrequent activity.
I also really respected Joel Spoelsky so didn’t really have a constructive criticism as the site worked pretty well.
Has it changed a few years ago? When I started 3 years ago, I could answer right from the start and I got the ability to vote quickly enough, after a pair of vote on an answer, without having to do menial tasks every day. Reputation can also be gained with edits, is that what you are talking about?
I don't really have an answer to the problem, SO has some very smart people working for them who, I'm sure, think about this issue. For some reason technical discussions held by competent people on the internet seem to trend towards dumpster fire. I've also noticed this phenomenon on photography discussion groups.
I've seen moderators of small communities hold off the effect by setting a good example, using a deft touch, and not letting the community get too big.
My suspicion is that once the number of commenters gets much past Dunbar's number [1], the universal fall into "default jerk" happens. Once that's taken place, you're stuck in an Eternal September.
Communities in the real world don't scale well. I'm not sure why programmers expect them to on the Internet, with its well-known capacity for dehumanization.
And perhaps make it so that DOWNVOTES CAN BE DOWNVOTED (provided a written reason is given for that as well).
I think they don't have enough (or any?) moderators working for them. They rely too much on making profits with the free help of trolls.
I understand it would be hard for them to change the power of the troll-users by now. Perhaps we simply need a new Stack Overflow, some competition.
If the person who answers actually needs the points, I'll give that some consideration, but it seems like a lot of the time the solution is offered in the comments anyway. I don't know why that is.
Every once in a while I'll swoop in on a basic question and try to answer it before anyone else notices.
I've been yelled at for doing that on Stack Exchange sites other than SO.
Posted a week later with a friend's account and it stayed but my friend panicked at loss of points and inability to do their job without them and removed it themselves (tho gave me answers firtst).
(Also, if many people read your answer and approve of it, then eventually you'll get some votes too.)
Having said that - there is some merit to sticking by the (nastily-enforced) standards. It does get people to improve their answers. Not saying that I approve of people's conduct on SO - it can be quite terrible.
For instance "how do you concat strings" for various languages is highly upvoted. Senior advice about general code structure and maintainability doesn't really have a title.
I'm a reasonably senior engineer, I've been lucky to experience an extraordinary breadth of technology in my career, and I love helping people learn to program... but I just don't have the time or emotional energy for SO's top posters to pick apart the minutia of every word I say in an answer. The ROI for me is nil.