I've been a history buff for awhile, including studying history at college and really admire this subreddit and all the hard work the historians put in here. You are all amazing! So, I hope this question doesn't come off as rude, I'm just curious about a perceived practice.
There's something that's bothered me since college, when I first encountered English history. I've noticed that when historians of pre-modern and late medieval England cite quotes from primary sources in their works, they rarely translate them to Modern English (although there are exceptions). This seems to be particularly common with Early Modern English. I've seen this practice in everything from textbooks, to secondary literature, lectures, semi-pop history books, even in answers on this subreddit. For example, in this answer, the early modern English is not translated to modern English and I remember reading works from Alastair Minnis that leave "Canterbury Tales" lines untranslated. Yet, if a historian is writing in modern English about medieval France, or Classical Greece, or any other field, especially if the intended audience isn't just other established scholars, they almost always translate the primary-source quotes they use in addition to providing the original.
While I understand that Early Modern and Middle English are easier for a Modern English speaker to understand then say, Tang-era Chinese, it's still quite different from Modern English. The spellings are far different, there are routinely words I don't recognize, and even words I "figure out" sometimes have much different usage and connotations now then they did hundreds of years ago. When reading these passages, I often end up misinterpreting them, which diminishes my ability to understand the source being cited and the arguments of the scholars.
Again, I don't mean to be rude, but I find this frustrating and believe that it makes the history of pre-modern England unnecessarily inaccessible. What's the value of leaving Middle and Early Modern English quotes untranslated in a historical work written in Modern English? Are we just supposed to understand Chaucer and Gorboduc as is? Am I just stupid?
You're not stupid! But there are reasons why we do this. As a literary scholar myself, I fall on the opposite end of this: if I come across translated middle English in an academic work, and the original isn't there, I find it incredibly irritating, because I need to go find and look at the actual text to make sure it actually says what the person says it does. We literary folk are really invested in what specific words mean.
I'll give you an example, related to my work (and to Alastair Minnis' actually, he's a huge source in my subfield)
Makar, Auctor, Expositour, and Scritor could all be conceivably translated as "author" in modern English, but they all mean subtly different things.
Makar is usually but not always Scottish, and connotates a skilled and artful poet
Auctor is an important word related both to modern "author" and "authority." It means an authoritative source, someone wise, trustworthy, possibly divinely inspired.
Expositour is a commentator or exegete, someone who explains authoritative texts like the Bible.
Scritor can mean a lot of things, but it often means a scribe, copyist or technical writer, someone who produces text but doesn't create them.
Now, if you, like me, are interested in medieval ideas about authorship, these distinctions matter A LOT, so if, say, Minnis translated the text and didn't distinguish between them, it would render his scholarship inaccessible at best, and meaningless at worst. If he's aware of the distinctions and not printing them, I need to do a bunch of leg work confirming everything. If he's WORKING in translation, then he may not be aware of essential distinctions and it can render the scholarship worthless.
It's also important to consider audience here. Most of Minnis' work in particular is quite technical, and aimed at other scholars of medieval literature, almost all of whom are going to have at least some knowledge of Middle English, and many of whom, like me, will really want to see the original text. Since space is always a concern, if a writer aiming at academic audiences had to choose between translation and original, they're going to go with the original.
As for writing on here, some of it is a time concern. I tend not to provide translations because usually they don't exist or I don't trust them very much. Because basically everyone studying medieval English has to learn Middle English very early in their career, what translations exist are often pretty amateur. Translating poetry well is HARD, and putting in that leg work is often something we don't have time for. And fundamentally, work loses something in translation. I can't write Chaucer's verse in modern English nearly as well as he did in Middle. Sometimes, like with foreign languages in anglophone scholarship, you gotta pay that price, but any time it can be avoided, it will be.
Lastly, I want to refer you to a useful resource that may help you going forward. https://quod.lib.umich.edu/m/middle-english-dictionary/dictionary
This is the middle English dictionary, it is extremely good, and I always have it open when I'm reading Middle English. Even though I'm fairly good at it, there's always some words I don't know and some context I'm missing, and this is my one stop shop for finding out.