We're all familiar with the Dr. McKay panicky whiner type character. If we don't have one in our own family, then we probably know one at work.
His (or her) first impulse when something goes wrong is to let his emotions run wild. Instead of contributing to the solution of the problem, he gets in the way of others who are doing their best to remain calm so they can solve the problem.
The panicky whiner character is irritating beyond belief, but he is actually very useful in advancing the plot. His obnoxious whining is basically well-disguised exposition. Also, he illustrates what the protagonists must NOT do, which is give in to panic.
The funniest character of this type was USMC Pvt Hudson in James Cameron's SF classic "Aliens."
Hudson: Well that's great, that's just fuckin' great, man. Now what the fuck are we supposed to do? We're in some real pretty shit now man...
Hudson: That's it man, game over man, game over! What the fuck are we gonna do now? What are we gonna do?
Hudson: Seventeen *days?* Hey man, I don't wanna rain on your parade, but we're not gonna last seventeen *hours!* Those things are gonna come in here just like they did before. And they're gonna come in here...
Hudson: ...and they're gonna come in here AND THEY'RE GONNA GET US!
Hudson: Wow, that's beautiful. That... that tells it all.
Hudson: I don't believe this, I don't fucking *believe* this.
Hudson: Oh, maaaaaan and I was getting short. Four more weeks and out, now I'm going to die on this rock. This ain't fair man.
Hudson: Four more weeks.
Hudson: How? The transmitter was on the APC. It's wasted.
Hudson: Think of what? We're *fucked*!
Hudson: We're doomed now...
Hudson: Oh yeah, sure. With *those* things running around? You can count *me* out.
Every time the Hudson character, played to perfection by actor Bill Paxton, started whining, I couldn't stop laughing.
Fortunately McKay, like Hudson in "Aliens," eventually pulls himself together and redeems himself.