Socio-economic WorldBuilding is not easy, but certainly on-topic
From What topics can I ask about here? (emphasis mine):
Effects of events or world elements, including biology, technology and magic, on specific aspects of that world's societies, cultures, and environment
The thing is that a question should aim to build a world and focus on aspects of society if you are interested in socio-economic worldbuilding. There is absolutely nothing wrong with the topic itself and it is most certainly a fascinating topic where we have far too few questions on the site right now.
I don't see how our help center discourages socio-economic WorldBuilding and I disagree with the close reason being off-topic.
But: you have to be sure that a question is not too broad.
I know what you are thinking: That guy didn't read my question. I explicitly mentioned that the question I referred to is not too broad!
Let me explain myself:
To cite from the question that you are using as a reference:
What alternative human society/economy systems are there that already exist or are being built.
That is the whole question.
Apart from a missing question mark this is basically the definition of questions that are too broad. This user wants a list of all the systems that have been developed over the course of all of humanity's existence and all systems that are currently being developed.
The user even explicitly says this as his reason behind asking, as you can see at the end of the question:
I am making a list: http://www.tricider.com/brainstorming/30EjgBCUsBp
Note that the link even contains the word brainstorming.
Questions that ask for endless lists of everything that has ever been created and is currently under development, plus inviting what people think of at the moment of writing an answer are not a good fit for the SE format.
To cite a question about this on Meta SE - Why are “shopping list” questions bad?:
They are open-ended; there is never one perfect answer to them.
They outdate incredibly quickly. This was what turned me against shopping list questions: if you look around on Stack Overflow, you will find plenty of 2010 "what's the best xyz" questions whose answers are hideously outdated now.
They tend to attract a lot of spam and/or link only answers
I think the reference is a shopping request. It gives three examples and then says "Please give me more, I am making a list".
There are no criteria for what makes a good system.
Therefore it's not that there I have no answer - there are too many answers that fit all of the non-existing criteria. How should I judge answers? "Yeah, it mentions a system. Upvote!" is not how the site is supposed to work.
Did it work out? Is there some proof of concept? In which situation is the system useful? What were the strengths and weaknesses? How many people use that system?
The OP is asking for a review of socio-economic cultures, ostensibly to use as a reference when building his/her world.
No. The OP is not asking for a review. The OP is not asking for a discussion of Pro and Con or similar things. The OP is looking for a list, probably so that they could later choose what fits best to their setting. The OP does not want people to talk about the given examples, but provide as many more examples as they know.
You can even see it with the existing answer. It perfectly answers the question by stating a system and giving a few key points about what it means. But there is no review, no comparison. It's just a summary of one system. Another item on the list.
If they really wanted to make this on-topic they should have a look at the worldbuilding-resources tag and see if someone could come up with an existing list somewhere on the web. That might be a way to go about shopping questions here on WorldBuilding if used appropriately, which is now, while writing this answer, making me question the usefulness of its existence.
If the OP asked for a system that would satisfy certain conditions and then limits his constraints it would be a perfectly fine question for WorldBuilding and I would love to see more of such precise socio-economic questions.
- The reference was rightly closed
- The close reason is wrong
- Socio-Economic questions are already perfectly on-topic
- Shopping questions asking for lists are off-topic