Well, I am going to play Devil's advocate here and ask "Why the hell not?" If Faramir has brown hair in the film I am going to point it out and ask "Why?" Why shouldn't I be allowed to complain?
I think the problem is that people confuse levels of seriousness. No, people do not need to get upset about minor changes, but neither do people need to get upset when people point them out.
This is, after all, a Tolkien discussion board. We will get into the finer points that 'normal people' would not think about. Call me a pedant and I will smile back.