I got in this kind of argument with my mom over the movie. Humanizing them doesn't make sense, because they are not human. It's kind of like going to Africa and calling black people who have never set foot out of their home countries 'African-American', because you've gotten so tied to political correctness in the United States. I can only imagine doing such a thing would be vaguely insulting. In the Case of the Prawns, why would you think they even want to be humanized? Why would you think they want to be seen as equatable to human beings?
They are sapient entities for certain, but they are not human. In an attempt to humanize them, they were given human, English names; I don't think Christopher Johnson was alone in that regard. The effect may be humanizing, but it is de-prawn-izing. When African slaves were brought to America, new, English names were imposed on them for similar reasons, to remove them from their culture and impose a new one that was considered by the Americans at that time as somehow better.
It is not adequate for me to look at an alien entity and feel some sort of equality with this being due to aspects that I could call somehow humanizing. Rather, I feel the proper reason for one to look at an alien as an equal is because we share the common spark of consciousness, something more universal than any human trait.