Explain NGE to a newb

So I caught the last 40 minutes or so of "Neon Genesis Evangelion Final" and am totally confused.

Why is Shinji strangling Asuka at the end?

Did anyone else think this was one big pretentious trying-to-be-art mindfuck rather than having some real underlying plot or message for the viewer to understand?

After reading about the creator of the series suffering from depression, the whole film really seemed like the expression of one crazy guy's screwed up mind. I'm sure it's meaningful to him, but to regular sane people it's meaningless.

Honestly, I don't understand why people dislike EOE.  A lot of people say it's a slap in the face, but I see it as a fine way to end the series, rather than have everyone live happily ever after and make a sequel.  I like to imagine end of the world scenarios that are greater than any individual effort to try to stop it, and having one character be responsible for it is the ultimate weight of guilt and responsibility, far greater than any being should be able to handle.  Don't appreciate it for being about a couple characters, appreciate it for being about the end of the world.  I haven't seen any good armageddon movies that come close.