It depends on the context. If somebody calls me an ignorant person, they are implying that I don't have a lot of knowledge in general, and that would be an insult. But if they were merely saying that I was ignorant with respect to a certain body of information that I don't know, then of course that isn't an insult, it's just a fact. Ignorance is nothing to be ashamed of, as long as you're not ignorant of something that you definitely ought to know by now. Recognizing the extent of your own ignorance is the first step towards increasing your understanding of the world.