Understood, this is a concept illustration and not final art. Nice enough to be encouraging. When you put any work into public view, you will get both positive and negative comments. Expect that.
Any comment means you are attracting people to have a look, a good thing. Stay positive during this public reveal. Henry Ford made the model T automobile, which is ugly compared to a modern Ford car -- but he had something to work with.
Not all negative comments will be intended to discourage you. Some may have very good advice. Keep on going.