From the definition phase of latin.stackexchange.com:
Latin’s mixed up with almost everything in Western civilization
Latin is important because it's intertwined with a lot of things historically, and even some things today. Latin was not simply the language of the Roman empire; it was Europe's international language of science, religion, law, administration, and scholarship from about 800 CE to 1800 CE.
Even today, if you're interested in biology, you need some grasp of Latin to understand the scientific names of species. Anatomy is filled with Latin. Why is the cerebral cortex named after bark? Lawyers need some grasp of Latin to understand legal terminology. I still hear philosophers inventing new Latinisms that evoke old ones. The Catholic church used Latin in unique ways for its rituals and to define its organization. Cicero's style was tuned to the needs and conventions of Roman speechmaking. Grammarians have often tried to make sense of the grammars of other languages by mapping them to Latin grammar—sometimes with dubious results. If you want to understand why English verbs in their -ing forms are confusingly called gerunds as well as participles, you'll soon have questions about Latin grammar—and the thinking of Latin grammarians.
The Latin poetry of Ancient Rome is widely considered among the most extraordinary ever written in any language. To understand it, you need to understand something of the customs, history, and politics that it's mixed up with. When Vergil says Dēsine fāta deum flectī spērāre precandō,* is he engaging in heresy or just stating the common wisdom?
A language is not simply a code of words, meanings, and rules; it's a bunch of pointers to shared cultural reference points. So, yes, I think questions about the surrounding cultural, intellectual, and historical context are on-topic. Otherwise, it wouldn't really be a site for questions about Latin.
A rule to maintain focus
However, to keep the site focused, I suggest that we require that every question explicitly refer to some specific aspect of the language, which should be the focal point of the question. To illustrate: Asking for the meaning of a Latin word used in some quirky way by a Scholastic philosopher is fine. But asking about Scholastic philosophy without regard to its peculiar uses of Latin is not.
Yes: "Who coined this word and why?" "What pagan ritual did this phrase refer to?" "Why is this vowel different in English than in Latin?" "Did anyone actually use regimented Latin for anything other than treatises on logic?" "Why did people start abandoning Latin in the 1700s?" "How was Latin commonly taught in the Renaissance?"
No: "Why were Latin-speaking jurists/logicians/priests/etc. so interested in ⎯⎯⎯⎯ ?" "What's the procedure in canon law for ⎯⎯⎯⎯ ?" "With what rituals did Roman sailors try to placate Neptune?" "Who in the Aeneid is supposed to represent Octavian?"
A factor to consider when resolving borderline cases
Here's a borderline case: questions about stories you read in Latin, like "Regarding the story of Comātās and the Honeybees, was it customary for masters to lock their slaves up in chests?" The same classicists who answer the language questions are also the best people to answer that question, so it would be a shame not to answer it. But it would be better to focus the question on the language rather than the story.
I propose that we be a little more lenient if a question about a Latin fable is asked in Latin: "Quae accurāte est arca, et solēbant dominī servōs in arcīs inclūdere?" It still helps that the question is about a specific word. Allowing questions about anything if they're expressed in Latin would defocus the site, of course. But it could be a nice way to decide the inevitable borderline cases.
* "Stop hoping to bend the will of the gods by praying."