It was discussed that we progressively introduce strong female characters that boys can like. They will NOT automatically accept a lead strong female if there aren't strong females on the side leading up to it. It has to be eased into. An d Pixar is planning a story with a female lead. It's called The Bear and the Bow and it comes out in a few years.

But that aside, to call it sexist is just SO ridiculous, I'm sorry. You can say you wish that Pixar would have a female lead and that is totally fine, but it is a HUGE stretch to call them sexist because they haven't especially since they continually write strong women (as noted, often stronger than the actual male leads), lead or not.