I was subscribed to it the first week it existed so I know that your story is completely fabricated. The origin is even in the subreddit wiki…
/r/NoStupidQuestions was founded in February 2013 for people to feel free to ask the questions they might be embarrassed or ashamed to ask elsewhere. Inspired by this thread and specifically this comment
Look at the questions in that thread. It was always about silly little questions
Silly little questions as in common sense stuff. “How often do I really need to wash a hoodie?”