How is it not one of the better questions on SO? It's educational, it's on-topic, it's more cerebral than the usual questions about jQuery, it has high quality answers, the question itself is as clear as day, it's interesting, and it's very popular in terms of views and upvotes.
There's a degree of opinion in most answers anyway especially as there's often multiple ways to do the same thing and every answerer will have a preference of some kind. I don't necessarily see this one as a particularly subjective discussion anyway, or why you think I'm trying to make SO be something it's not. In any event, why are marginally subjective discussions are a horrible thing anyway in a Q&A site?
How can anyone answer "really useful but are unknown to most programmers"? They are so useful we don't know about them? Aren't the answers, by definition, known, to a lot of programmers? Useful for what exactly?
I think I heard this criticism of SO for about 1 million times and this is the 1 million + 1 that tripped my fuse, so apologies for that. This question, and the answers, though IMO are bits of trivia and opinions more suited to a blog post.
Does it have some marginal usefulness in exposing some people without background to some random data structures or algorithms- maybe. The question is still there, it wasn't deleted, so SO is acting as the resource that you'd like it to be. If it's your first exposure to data structures I think there are better options out there (text books, online courses). If you are looking to solve some particular problem this is probably not the best resource. So it just stands as a (maybe interesting) bit of computer science trivia.
There are endless subjective topics that are tangentially related to programming and may be fun/amusing/interesting but SO is about things that have answers, not about discussions. I like it that when I have a question I can search and get a good answer for it, not just someone's opinion. For entertainment value and interesting things I go to other places, such as HN...
> The question is still there, it wasn't deleted, so SO is acting as the resource that you'd like it to be.
Try asking such a question today, or any time in the last couple of years!
> So it just stands as a (maybe interesting) bit of computer science trivia.
Just because you label it trivia doesn't necessarily mean it wasn't important to the asker or the thousands of people that read, commented, and upvoted. Just like people asking about jQuery, the asker had a question in mind and wanted to crowdsource the answer.
> but SO is about things that have answers
An opinion can be an answer too.
> For entertainment value and interesting things I go to other places, such as HN...
Why must the answers on SO be bland as tofu? You seem to give the impression that learning and the SO answers must be plain and dull, and any hint of entertainment must be quickly quashed. I see nothing wrong with being entertained and educated at the same time, especially as things that are entertaining tend to be more readily recalled.
I didn't disparage vegetarians, and not even their diets. Tofu on its own is bland and that's really hard to refute. Tofu with other stuff is delicious.
The problem is that SO is not for entertainment. It's not even really for education. They (the site's operators) want it to be an injective mapping of google queries to solutions. You don't need to become a better programmer. You need to keep coming back to SO to ask more questions. On the other side they need to supply a steady stream of middling difficulty questions, because everyone isn't John Skeet.
Nobody is going to be working on a project and say "My client requires the use of obscure data structures, better Google some!". You can bash the multitude of jQuery questions, but having worked in a variety of settings, some people need things spelled out for them. You need a lot of simple questions with alternate wordings, different permutations of libraries, etc. Even though you can generalize these answers, they're hard to find from Google, and a lot of people will read "Undefined variable foo? Nonsense, my undefined variable is baz. Better open a new ticket".
There's a degree of opinion in most answers anyway especially as there's often multiple ways to do the same thing and every answerer will have a preference of some kind. I don't necessarily see this one as a particularly subjective discussion anyway, or why you think I'm trying to make SO be something it's not. In any event, why are marginally subjective discussions are a horrible thing anyway in a Q&A site?