Also consider that by making that choice the director/DP frees themselves from possible studio notes and endless discussions on how 'film look' to add, whether or not it should be toned down or up etc. If you want something to look like Ektachrome you are gonna get that by shooting Ektachrome, always.

Please correct me if I'm wrong, but isn't green used as the green channel has a higher resolution compared to blue and red because of the way photo sites are aligned on the Bayer-filter?