G'day Deborah!
There were other members of the Murdoch family who chose not to see the movie (his nephew told me he had no intention of viewing it) - I can understand why. There were also family members descended from or otherwise related to other officers who were troubled by the movie or found depictions of their relatives objectionable - members of the Lightoller, Moody and Boxhall families spring to mind. On the other hand, while he didn't agree that the depiction of his father was quite the man he knew, Lowe's son thought Ioan Gruffud did an admirable job in the role.
I've never used the phrase 'only a movie', but I agree with Deborah we don't need to lose perspective over this. In other threads, I have argued strongly for what I believe are the movie's strengths and weaknesses (and have discussed at great length the depiction of the deck officers). I don't feel I have to like - or agree with - every aspect of the flick to still enjoy the parts that I felt worked. At the same time, nothing will ever make me pleased with, for example, how Moody was depicted, and I've made that point.
If we were to ask 50 Titanic researchers to make their own movies, I think it's safe to say we'd wind up with 50 very different interpretations, and people would be disputing some of the elements in these interpretations just as strenuously!