Exactly. He could have included some scenes during the "break away" scene where he had Elrond trying to convince Arwen to run off to The Havens.
For the same reason Glorfindel is not in FotR - minor characters must be excised to keep the audience from losing track of who is who. Erkenbrand is replaced by Eomer, who Gandalf DOES bring back to help.
Glorfindel is not in FotR b/c Jackson wants to being Arwen into the story. It has nothing to do with eliminating a character who would only show up long enough to loan Frodo his horse. I can actually understand this modification, even though I mildly resent the fact that Jackson doesn't think a movie is any good with out the sex appeal of a Liv Tyler.
If you listen to the Director's commentary you'll find that both reasons went into the decision to cut Glorfindel. Jackson was concerned with trying to introduce too many characters, i.e. Gil-Galad, Glorfindel, and he needed a way to introduce Arwen because she is the reason Aragorn is doing the things he is doing.