'The Divergent Series: Allegiant'In its opening weekend, "The Divergent Series: Allegiant" was supposed to give the still-strong "Zootopia" a run for its money. Analysts predicted that both the hit Disney cartoon and the third installment of the YA franchise would reach about $35 million.

As it turned out, "Zootopia" did even better than expected, losing just 26 percent of last week's business and grabbing another estimated $38.0 million, good enough to spend a third weekend in the top spot. But the competition wasn't even close. "Allegiant" came in nearly $9 million behind, with an estimated $29.0 million. That's the franchise's lowest opening yet.

"Allegiant" should have done a lot better; at the very least, it should have held its own against a movie that's been out for almost a month. So, what happened? Here are five areas where Tris and her team ran into trouble.

1. Negative Reactions to the Book

Like other young-adult fantasy franchises, the "Divergent" movies have banked on the popularity of the best-selling books they came from, as well as the storytelling skills of the authors who created them.

But even among fans of Veronica Roth's novels, "Allegiant" was a controversial book that outraged many readers. Even though the ending that prompted the "WTF?" reaction from readers doesn't happen yet in the "Allegiant" movie (fans might see it in 2017's "Ascendant"), that sense of disappointment surely kept many "Divergent" fans from wanting to see even this first half of the two-film finale.

2. Splitting the Movie In Half

The tactic of splitting a franchise finale into two parts, which made some sense with the plot-heavy "Harry Potter and the Deathly Hallows," has increasingly come to appear to fans as a cynical cash grab.

The first-half-of-a-finale movies, like "The Hunger Games: Mockingjay, Part 1" or "Allegiant," often feel like throat-clearing, all exposition and set-up and no payoff. They don't feel like organic, stand-alone movies, like the earlier chapters. The stories and characters feel stretched thin, as if to justify such a film's running time. It's no wonder that fans often feel like skipping the second-to-last movie in a series and waiting until the actual finale. It feels even more problematic to split the adaptation of a book few liked in half -- why would they pay to see two installments when they weren't too keen on the whole thing the first time?

3. The Execution

"Allegiant" might still have drawn fans if the film had been well-made. But it wasn't, according to critics, who gave the film a terrible 10 percent on Rotten Tomatoes. Ticketbuyers weren't much kinder, giving the film a B grade at CinemaScore, indicating weak word-of-mouth.

4. Poor Timing

The third week in March may have worked well for the first two movies, but this time around, "Allegiant" ran into tough competition. There was "Zootopia," of course, which was built to appeal to older audiences -- as well as tots. There was also the new "Miracles From Heaven," the faith-based drama starring Jennifer Garner, which did better than expected with an estimated $15.0 million.

There's "10 Cloverfield Lane," which cut into "Allegiant's" audience to earn $12.5 million in its second weekend. And for older teens, "Deadpool" is still raking it in, earning an estimated $8.0 million in its sixth weekend. Even without the R-rated superhero movie, there were still plenty of acclaimed, teen-friendly options to compete with Tris' latest PG-13-rated outing.

5. Fading Interest In the Genre

The problem may be bigger than "The Divergent Series." It's also possible that the whole young-adult fantasy/post-apocalyptic future genre is played out. "The Hunger Games" saw diminishing returns with the final two movies. The second "Maze Runner" movie in 2015 earned 20 percent less than the first one. The latest attempt at launching a franchise in the genre, January's "The 5th Wave," stalled out at around $34 million.

It's clear that distributor Lionsgate expects big things from the franchise closer, "Ascendant" -- instead of releasing it next March, it's coming out June 2017, at the height of summer blockbuster season. But if the audience has moved on, not just from "Divergent," but from the whole genre, then summer dollars aren't going to redeem the downturn the series is seeing.

If the studios don't figure out what the next big thing is for the audience that made Lionsgate's "Twilight" and "Hunger Games" franchises so huge over the past decade, they may as well rename the final movie "Obsolescent."