Question: A question such as [this](https://christianity.stackexchange.com/questions/8875/if-homosexuality-is-a-sin-why-isnt-abstinence) seems to be objectively verifiable via the Bible, so I see no reason for it to have been closed based on the claim that it's "not constructive". It is based solely on the belief that homosexuality is a sin, and if it says that it is a sin in the Bible, then the answer is yes. If not, the answer is no. It's a closed ended, yes or no question. That being said, what is the problem with this question? Is it because it's a "why" question? Where does the problem lie with this question, which simply highlights a contradiction/ambiguity in Christian teaching and seeks to rectify it?

Another issue is that it seems that if it had simply been worded differently, it would have been acceptable. For example, if it were worded, "Given that homosexuality is a sin because it impedes procreation, why is abstinence not a sin as well?", there would be less room for debate and discussion, which is good. But the question would still be the same. So can a question be closed simply on the grounds of its wording? I would simply like some pointers, as two of my questions were voted down, and I really would not like to look at this community in a negative light, and I do want to continue here. So please, any tips on what was done wrong in the question I mentioned above?

Answer: 
"Is X a sin?" questions are usually problematic. They are usually unanswerable unless you address your question at a particular Christian tradition and interpretation framework.

Question wording does matter. A question that *could* be acceptable if was worded differently should expect to be closed until it *is* worded differently. Once it had been edited into shape, the community can vote to re-open it (with less votes than it took to close it).
For one, one of your primary assumptions of the question is not a consistent interpretation of how Christianity views this subject. This shows a lack of research effort on your part in asking the question. 

The fact of the matter is that 

* Christianity does not universally condemn homosexuality as a sin - various groups view this practice differently, assuming we all do the same thing shows a serious lack of understanding of how vastly different christian denominations and doctrinal positions are.
* Those that do condemn homosexuality as a sin do it for a variety of reasons. Again, you're showing a lack of research here.

Finally, your question was asked in such a way (along with your other question) that does not seek to actually educate yourself on the views of Christians, but instead is seeking to stir up trouble and dissension on this site. 

So we have a false premise, a lack of research and a combative question style. That's a closed question to me.