is closed because "opinion based". Alternate-history is by definition opinion based. Sure you can look up GDP numbers, population size and so on but you can only speculate how these data would influence one or the other historical decision that is changed. If you allow questions about alternate-history you must allow questions and answers that are opinion based. A good answer starts with facts and reason and discusses how they affect the issue at hand but at the end of the day, it is just an opinion and we will never know if it is close to reality or way out there. Very similar to people predicting the future (although in this case there will be a result/answer sooner or later, but until then, it is just a more or less well founded opinion).
Very often questions are closed for being opinion based when the OP does not give a metric for evaluating the answers and picking a "reasonably good one".
In your case you simply asked "what would happen?", and even added
Without giving a time constraint or any other constraint.
Our help center clearly states that one should avoid asking questions where, among others:
- every answer is equally valid
- you are asking an open-ended, hypothetical question: “What if ______ happened?”
And you managed to get both bullets with one question.
So, no, it's no joke. You question as asked in this moment is opinion based and aptly closed.
It's very possible to have non-opinion question which fits in the tag of 'alternate history'. The trick is to be as absolutely concrete as possible when asking your question and to specify it over as thin a subject as possible. Also, set up crystal clear facts so that anyone researching it would be able to find relevant information to the subject. And, on that note, it helps to ask question about things which have a lot of objective information available on them - asking a question on anything that people have a lot of opinions about isn't going to be helped. A question like:
Suppose Alexander the Great hadn't died and went to fight against China. Could the Chinese Army at the time reasonably fight against his army?
How would the Battle of Gettysburg be affected if the Battle of Little Round Top went in the favor of the Confederates as opposed to the Union?
Suppose the secret to Damascus steel was more widely spread such that everyone could have a Damascus sword. Would that makes conflicts in the Middles Ages have a significantly higher casualty rate?
Also, so help me if anyone actually asks these questions without crediting me. I'll notice, trust me.