If I challenge you it's a sign of respect. Please do not take offense. If I didn't think your thoughts are valuable I wouldn't bother.
I have a pet peeve about rhetorical questions. When I ask a question it's a question. When I make a statement it won't be followed by a question mark. (Usually. I've realized I slip-up at times. Feel free to call me out when I do. It's helpful to me.)