There are valid reasons that the question was closed. Those reasons are known and expected to be enforced.
I'm just perplexed by the trend over all, especially with Wikipedia, for people to act like the internet is a library and shelf space is running out. Why would a site owner limit their user's contributions in any way except to conform to the law, and prevent trolling, spam, etc? Who knows how much value the next answer might have provided readers if they hadn't closed it down?
This is not to say SO or Wikipedia has the balance right; but it's a sensible reason to "limit their users' contributions."