I appreciate the confidence that comes through in a work when the writer does not feel the need to overly explain his points.  He believes what he writes and writes it.  Then it is up to posterity to decide whether they find value in it.  Some may call this overconfidence or arrogance, but unless you have to defend your ideas to a dissertation board, or a classroom, or an instructor, a bit of arrogance in your beliefs may not such a bad thing. People will disagree with you, even if you well support your argument, but they will trounce you if you don’t believe in what you write.