I think it's a behavior from work got carried over answering questions in StackOverflow. Usually when there's a request from client/PM/PO, I usually ask them what they want to achieve by requesting said feature, usually after asking that question they will think and find out that making that pet feature is not the best way to achieve that goal.

As a Software Engineer we're conditioned to respond that way to a question, and when we go to websites that's specifically to answer questions, we are still answering questions from fellow technical people in that same mindset, which is not helpful.

However, I've used the condescending answers from StackOverflow to my advantage. Sometimes in a project we'll get businesspeople with a technical background, either they used to be an engineer 15 years ago or they studied computer science in university but transitioned to product management after graduation. If they are really insistent on some technical detail, I usually created a StackOverflow question based on their request and show them all the comments telling how stupid that idea is.