Why Men In Black: International Failed
3. All Of The Interesting Themes Were Cut Out (And It Shows)
Though these reports are of course unconfirmed, the idea that the movie's story was chopped up and changed mid-filming would explain the glaring flaws in the final cut. As mentioned earlier, the character arcs for M and H both disappear about halfway into the movie, paid lip-service to in the final scene like either hero had a profound journey or fundamentally changed as people.
It's the villains that suffer the most, though. The original intention to bait-and-switch the main antagonists and reveal them to have been looking for a way to save their world rather than destroy others kind of comes through, but it's obfuscated by poor storytelling. The shape-shifting baddies sit out huge chunks of the movie, showing up only to provide a quick set-piece, with the movie never bothering to explore their origins or motivations in any detail.
Likewise, the real bad guy, the mole inside MiB, is at once obvious and, again, confusing. Their motivation, and even the species they belong to, is never made totally clear, even when they're offed in the climactic battle.
How much these storytelling issues had to do with the alleged rewrites and how much they were already baked into the DNA of the original script may never be known, but either way it's clear the more interesting themes and narrative points were stomped out for something safe and, ultimately, boring.