“For artistic reasons … it’s really important that we do an original film a year,” says Catmull ... “Every once in a while, we get a film where we want or people want to see something continuing in that world — which is the rationale behind the sequel. They want those characters, which means we were successful with them. But if you keep doing that, then you aren’t doing original films.” ...
It's good that Ed Catmull is pushing for original films.
But for monetary reasons, the conglomerate for which he works is (likely) pushing for sequels whenever and wherever possible. Because sequels make lots of money. And the "ka-CHING" is what Disney, Viacom, News Corp. and the rest really care about.
Original movies? Meh.