4Viper (Top Gun)
As the Base Commander at the Top Gun training facility, Viper is undoubtedly one heck of a pilot. But if he was any good at commanding, he would have kicked out Tom Cruise's Maverick the first chance he got.
To put it simply, Maverick was the worst possible soldier ever, as he wouldn't follow orders at all and always did his own thing--heck, it's right there in his name. "Hold up, Cracked," you say. "That was the whole point! Jerry Bruckheimer's heroes are always loose cannons, like the cops in Bad Boys! There's always an authority figure who lets them get away with it because they get the job done!"
There's a difference here. Those guys weren't in a job where one wrong move could, at best, wreck $38 million worth of high-tech aircraft, or at worst, accidentally start World War III. So here's Maverick repeatedly questioning the authority of his instructors and being insubordinate, getting his teammates and himself "killed" multiple times in mock battles, and clearly putting the lives of, well, everyone on planet Earth at risk every time he took to the air with live ammunition and Russians on his radar screen. And all he gets are a series of stern warnings.
But how do you enforce a man who doesn't play by the rules?
Incidentally, this is the freaking military we're talking about here. That whole insubordination thing is no laughing matter: Being contemptuous or disrespectful "in language or deportment toward a warrant officer, noncommissioned officer, or petty officer while that officer is in the execution of his office" is actually legitimate grounds for a court martial in the Navy.
It's cool. This is America.
If Viper needed any more convincing that Maverick was the wrong man for the job, the fucker manages to crash the previously-mentioned 38 million dollar plane and simultaneously kill one of his fellow aviators during a training exercise. Maverick then falls into deep depression--he clearly can't deal with death; not a good thing for a soldier. Viper's attempt to console Maverick is even worse: He tells the kid that the Navy covered up his dad's death, which would logically result in Maverick getting pissed at the Navy for ruining his dad's life and leaving.
Instead he somehow gets his shit together, graduates, gets into a single battle and then decides to be a flight instructor. This not only means that Viper couldn't even motivate him enough to be an actual goddamn fighter pilot, but now Maverick gets to teach a bunch of impressionable young aviators tactics that will get them all killed. Maybe this is why now we make sure to fight all of our wars against enemies who don't have planes.
3Captain Jean-Luc Picard (Star Trek Movies)
We're not disputing that the Picard from Star Trek: The Next Generation was anything but an accomplished diplomat who made intelligent decisions. But as others have pointed out, the bald-headed dude from the movies was a big dumb action hero who liked shouting lines and shooting things.
The problem is, of course, he winds up as an old guy whose greatest talents are drinking tea and giving scathing rebukes who insists on fighting the bad guys by himself anyway. This results in Picard getting his ass handed to him by an even older scientist in Generations, surrendering to the Borg at the end of First Contact and completely failing to stop the superweapon in Nemesis. The strategy of, "I'll just teleport over there myself and punch the bad guy!" should not be the go-to strategy for the captain of a large military vessel.
"I've got a plan!"
The only time Piccard gets the upper hand is at the finale of Insurrection, where he straight-up murders the defenseless villain who didn't kill him when he had the chance. Look, when you've got a gigantic muscular guy like Worf aboard who's already said that he would prefer to die in battle, there's really no excuse for risking your life, your ship and the entire goddamn universe because you want to be the hero.
The movie Picard also has a habit of criminally underthinking situations. The plot of Insurrection is that they discover a planet where there is this radiation that can cure blindness and let people live forever. Picard refuses to share this with the rest of the universe, because it would disrupt the lives of a few natives, completely ignoring that whole "needs of the many" thing Spock kept blabbering about.
"Let's go kill these assholes for fucking with this planet's shit."
Then there's the way in First Contact he brings down his entire crew to mid-21st century Earth and tells everyone who they are and what the future will hold, ruining everything Kirk tried to do in Star Trek IV. You have to like how the response to this was to reboot the franchise with a Captain Kirk whose entire personality revolves around poor decisions. That's right, just establish it right out of the box, guys.