Unlike normal film or anything else that is live action, in anime you can control Everything! The director, the animators, the voice actors, Everyone knows what part they have to play and what they will contribute to the whole final project.

This was my arguement in the anime ain't anime without tentacle rape node. As you have complete control in Japanese Anime, espeically over what things look like, there is a tendancy to make things as sexy as possible.

All these different channels mean something. Nothing is there by mistake (bad writing not included). If Shinji Ikari is listening to Beethoven's Symphony No. 9 in D minor on his SDAT walkmen then there is reason behind that. Evangelion is a very good example to use becuase the series director Hideaki Anno crafted so much detail into character development and religious and mythical symbolism.

Of course it makes your brain hurt. That's part of the fun. Trying to track everything at once, discovering why Unit 01 is purple or why the ending song is called Thanatos makes Neon Genesis Evangelion in particular, and most anime in general very interesting to watch.

To quote the master Anno Hideaki himself, "Even names that have no bearing on anything actually came from the countless rules that govern these things."