While I don't believe that anyone can be too beautiful, I do think that it's possible to be too beautiful to be an actor. This sounds kind of mean but it's true for me. Watching anything that Douglas Booth is in generally means that I'm watching him and not whatever it is. He's too distracting.
Also, people were critical of his Pip because he is too beautiful to play Pip. Estella is meant to be very beautiful but Booth far outshone her in the looks department. It just didn't really work.