Who walks around Disneyland thinking "Man, I wish there was more stuff to do here."? Attendance has been increasing every year, aside from a small dip in 2016, and attendance levels are at the highest points in the resort's history. People obviously aren't getting tired of it. They already had the area needed to expand Fantasyland (they could've open a Frozen land if they wanted a land based around an IP.)
There's plenty of options to enhance Disneyland while elevating DCA. Cramming the most successful film franchise (aside from Marvel) of all time in Disneyland and scurrying for quick fixes to generate interests in DCA to draw away the record-breaking crowds we're about to witness was not the best way to go about it.