I find it discouraging when I ask someone a question or two and they don't respond to all of them*, even if to say that they don't want to talk about a specific question. To be specific, I asked two questions recently and only one got a response.
In this case I decided to give a little nudge, I hope that it will not be an ongoing issue. Though sometimes I don't feel like responding anymore, unless the person asks why, because it sends me the message that what I ask is ignored.