Ever been asked the question, “Why?”  Don’t know about you, but it sometimes puts me on the defensive, like I have to somehow justify myself.  The other person may not be trying to offend you, but sometimes that’s how it comes across.  Maybe that’s why it’s sometimes better to ask “what” questions.  E.g. instead of “Why did you choose to go that route?”, it could be rephrased to “What were some reasons that led you to that route?”  Sometimes, that helps to engage in positive dialogue rather than someone being on the defensive (which tends to lead towards negative/argumentative) dialogue.

Try it; see what happens.