Cannon fodder bad guys and lazy writing
A common theme in movies is that the protagonists must face waves of "cannon fodder" enemies. These nameless antagonists who pose little threat represent lazy writing and are ultimately bad for the story.
One of the worst examples is the Orcs in the Lord of The Rings movies. Wave after wave of soldiers from this "fearsome" warrior are easily dispatched by the heroes, with little effort or difficulty. One human should not be able to kill several Orcs by himself. The LOTR movies are masterpieces of cinema, but having the Orcs dispatched so easily even when they have a significant numerical advantage in a fight completely buries them as a threat.
The Jem'Hadar from Star Trek: Deep Space Nine are another example. Genetically engineered by shape shifters to be perfect warriors, they are far too easily dispatched. A Klingon should be able to defeat a Jem'Hadar soldier in hand-to-hand combat, but humans should consistently lose, only winning with a heroic effort. The human characters certainly should not defeat several Jem'Hadar soldiers in hand-to-hand combat as easily as they do.
There are more examples of this than I can count. But here is the basic problem: When enemies are basically cannon fodder for the hero of the story to mow down at his leisure, there is no sense that the heroes are in any real danger when they go into combat. In the worst-case scenario, the enemies the protagonists face are a joke. The only time the hero is in any real danger is when he faces the big bad of the movie.
In my opinion, the stories would be better if the henchmen were more competent, especially if they are supposed to be fearsome warriors like the Orcs. While we know the hero is going to make it through the fight alive if we are only an hour into a ninety minute movie, it should not be an easy one, because that is just a waste of time. Giving the protagonist competent enemies to defeat not only makes the bad guys look like more of a threat, it also makes him seem much more heroic, because the odds he overcomes are much worse.