Why did he say that? He was a quite reasonable and objective man, so he speaks from that viewpoint. I have read much of his fiction and non-fiction. He had great knowledge and was quite reasonable. Blind believers have no objectivity and cannot be reasonable. I read many of his columns in two magazines for years, and read many of his books.
Obviously I can't speak for anyone else but because I am a believer in and follower of Jesus Christ and because the Bible is my final authority for faith and practice my answer to your question is, heaven will have the better company. It's a matter of what the Bible has to say to me about heaven and hell.
Benedict Arnold 