There are countless places on the Internet where people can get informal guesses about history. On reddit alone, we will happily direct people looking for that sort of environment to r/history, r/AskHistory, r/HistoryWhatIf; there's also TIL, ELI5, and AskReddit.

Ask Historians, on the other hand, is a community where readers can expect in-depth and comprehensive answers supported by current research. People asking questions here instead of r/history or r/AskHistory do so because of that standard, because they know it will be upheld.

What would you gain by visiting AskMathematicians asking for the Pythagorean theorem, to be greeted with a thread full of the quadratic equation, the formula for the area of a trapezoid couched with the disclaimer "I'm no mathematician, but", "I think I read once that in a 30-60-90 triangle there's something with root-3?" We're in the business of a^2 + b^2 = c^2 here.

The question of an "off topic" thread like in WritingPrompts comes up every time there's a popular thread on people's front pages or r/all without an answer in...in whatever time frame people get impatient, which can be as little as under an hour. Frankly, the moderators are not interested in the extra work of moderating that thread as well--and if you're reading AskHistorians to read AskHistorians, you're probably not interested in what people have to say.

If you are, you are welcome to submit the same or similar question to a forum where you might get the Pythagorean theorem...but you might get the speed of light, with no way to know which is which.

Bad answers are worse than no answers in almost every case, just look at what happens in almost every sub that doesnt practice a modicum of moderation.

It ceases to be about quality of information, and all about who just posts first for what actually gets read and taken away from it.

Or have a huge banner heading on the page

Questions and answers must be suitable for a university-level history course.