I recently had the experience of giving my latest script - a thriller - to my writing group. I've talked before about writing groups, so I won't waste much space discussing why I find them useful. That said, it's always great to know that I can give these guys a script and have a reaction within a week.
Notice that word: "reaction."
It's sometimes funny how scared we are as writers of critical opinions. When I worked at one agency, they made certain that none of the readers' names appeared on the comment section of the coverage. This was because they'd had incidents in the past where writers had gotten their hands on negative write-ups of their scripts and then tracked down the writers to confront them directly.
I honestly don't know what they thought they were going to accomplish. You can't argue against someone's opinion. Further, my experience is that if you confront someone about a review like this, they're only more likely to dig in because you've essentially just challenged their credibility.
If someone doesn't like your script, you're never going to argue them out of that reaction. You might be able to have a debate about what led them to that conclusion. It might even be valuable to understand why they didn't like it, but that's where it ends. You will never turn a PASS into a Consider by debating it - because it isn't a debate.
Subjectivity is just something that you have to accept if you're going to work in the creative arts. The truth is that no matter how brilliant a writer you are, SOME PEOPLE WILL NOT LIKE YOUR WORK. If you're a hack, you'll meet a lot of those people. If you're brilliant, they'll probably be in the minority.
This doesn't change the fact that the law of averages says that at some point, you're going to run across someone who isn't in love with your writing.
This is the most liberating thing to remember when you're getting notes from a non-fan: You don't have to take every note.
I'm not saying you should ignore anything critical. There's nothing to be gained by closing your ears entirely to negative reaction. I always assume that if this one person comes to me with these issues, some other readers (and eventually filmgoers) will have the same bones of contention. So why not try to understand the negative reaction?
When I'm getting notes from someone, the most important thing I remember is to listen. If I'm talking more than they are, I'm doing something wrong. I also make it a point to speak less to defend the work and more to provoke the reader into discussing their response. I might jump in and explain what my intent was, for then they might be able to assess where I was and was not successful with that.
The people who give me notes often attach a lot of suggestions to them. Some are helpful, some are not, and some would turn the script into an entirely different story from what I want to tell. I cherry-pick the notes that make sense to me and reinforce my vision of the story, and I discard the rest.
So the note that pisses you off because it takes the edge out of one of your characters? You don't have to take it. The suggestion that you cut a particular joke because one reader finds it offensive? You don't have to take it.
By the way, this isn't a license to be a jerk about it. You asked someone for their opinion, so be polite when they give it to you. Even when you know you plan on disregarding their suggestions, thank them. In fact, it should be easy to be polite because if you know it's not a direction you want to explore, why get all worked up over a hypothetical.
The more comfortable you are in the face of criticism, the more you grow not just as a writer, but as a person.