Matt Slick says on carm.org
The CARM discussion boards get about 1000 posts every day. It is not possible for me to read them all. It is only natural that I will ignore posts. In fact, I ignore virtually all of them.
Sometimes someone will post something to me about a complaint, an issue, a question, or a challenge and then when I don't answer right away -- or never get to it -- I am accused of ignoring them, or of not being able to answer, or of being a coward, or something else.
This isn't the case. But I will admit that sometimes I simply am tired and don't have the energy to continue a debate. I have a family, a full time job, regular preaching engagements, research projects on CARM, 50 emails a day to answer, and a host of other odds-and-ends that life demands of us all.
The fact is, I'm only human and can't be everywhere at once.