I have been watching Evangelion recently and asking myself this question.
What point is there to Asuka even being in the series at all, except as a
love interest for Shinji and a foil for Rei?

All she ever seems to do is stand there whining and bitching and
occasionally getting badly beaten in her Eva. I cannot think of a single
time when she ever actually does anything useful or helpful. It seems like
she was only added so that Gainax would have another bishoujo besides Rei
and Misato to sell toys and posters of.

She also has a voice that sounds a lot like fingernails on a blackboard.
Seriously - this girl has to be the most annoying character ever. I actually
found myself cheering during the scenes where she is getting her ass handed
to her (though she never seems to learn from the experiences).

The first few eps when it was just Shinji, Rei and Misato were great - I
think that the additon of Asuka spoiled the series, turning it into another
Tenchi Muyo style comedy for a while. It took a long time to recover.