You need to think in terms not only of "easy to understand the question", but also "easy for future users with the same question to find the answer". Given how often people are asking using these terms, how often do you think they're searching using these terms as well? And if they are using these terms, then would those searches pick up the questions which aren't, those which were changed after asking into being English-only?
I know a number of people in my local community who speak fluent English, yet still commonly use terms like "roza" and "namaz" instead of "*fasting" and "prayer", or even "sawm" and "salat". These are common terms among certain groups — English-speaking groups — to refer to specific Islamic concepts; at this point they're not even really "non-English words" so much as a type of jargon.
Experts, for the most part, understand jargon in the fields they're expert in; and if they don't, they typically understand the value in learning it rather than eliminating it. As Robert said back in the early days of the site, dumbing down the language used to make it easier for non-experts to understand is counterproductive, since you're basically making it easier for non-experts to answer the question rather than attracting actual expertise.