I, Boonie, don't quit! The super heroes quit! Watch. I'll explain.
In MOST super hero franchises, the super hero gets a good start during the first film, then second film pops up during which the super hero throws in the towel.
Don't believe me? I'll show you.
Let's go back in time to the early 80's: SUPERMAN! Superman starts off with the first movie. We get a beginners look into Superman's beginnings, we meet Lex, (we even meet Zod and friends for a little bit!) and Superman saves the day. Later we get Superman II, or Superman Calls in Sick. Lois figures out he's the man in tights, (duh Lois,) and so he's like, "Okay. Well, then I quit." He goes into the Super-Extractor, sheds his powers, makes out with Lois, gets his butt handed to him by some loser in a bar, then is like, "Uh-oh. Someone has to stop this Zod guy. If Batman's not gonna do it I guess I better go see if my mommy will let me have my powers back, even though she said she wouldn't. But she's a push over."
Then in the early 90's we get BATMAN! Batman actually doesn't start with the origins of Batman, oddly enough. (Oh, we get glimpses, here and there. For YEARS we couldn't have a Batman movie [not even animated] without flashbacks of the night Bruce lost his parents. Not that that's a bad thing.) No, we got the origins of the Joker however. Apparently if you fall into one of those vats of acid you see lying around everywhere, it doesn't kill you, in fact, you won't even lose a limb, or go blind or something! All that happens is your skin bleaches and your smile widens... which some people pay for. So then we get Batman Returns, and we have to wait until the THIRD installment before Batman quits. (That's probably because Batman's not as big of a quitter as the rest of these guys.) Eventually we get Batman Forever which comes with Jim Carrey, Drew Barrymore before she was famous, Nicole Kidman before anyone really cared about her, Robin, and Tommy Lee Jones in the worst role of his life! He does SUCH a horrible job. It's sad. We also get Val Kilmer's Batman what quits. Why does he quit? I don't know. Is it because he doesn't want to be a bad influence on Robin? Is it because of these repressed memories about the time he falls into a cave and a bunch of bats come out of it? For whatever reason, it looks like he's gonna call it quits, then he doesn't. It's pretty weak, but it gives us a title.
Let's skip ahead to the better Batman's, The Dark Knight series, so named for the best movie out of the trilogy. This time around we do get Batman's origins story, and it's a doosy! That all happens in Batman Begins. Then we get The Dark Knight in which, you guessed it, Batman almost quits. Because of the Joker's threats, Batman's THIS close to giving himself up when soon-to-be Two-Face steps up and claims the cowl and gets arrested in his place. I'm sorry. Did I spoil that for you? Have you really not seen it yet?
Okay, now let's rewind a little bit and talk about Spider-Man. In the first one we get his origin story, then POW, in the second one he starts to lose his way. He says things like, "I am Spider-Man no more," and "My back! My back!" He even ignores a mugging on the street! But, you know what, the X-Men aren't gonna swarm in and take care of Doc Oct! So, before the end Spidey puts on his mask again, then takes it off, then puts it on, then takes it off, then puts it on! Maybe if he kept his mask on it'd be harder for people to figure out who he is!
Now let's look at Iron Man. Iron Man I was another origin story. Yay! But in Iron Man II he gets sick, starts to die, quits his job, and thinks, "Yeah. I'm gonna die. So I'm gonna throw a big party and not be the hero Pepper thinks I should be," or something. Anyway, he doesn't die, and he doesn't quit.
But let's look at the X-Men... no let's not. The fact is Wolverine is ALWAYS quitting the X-Men, and nobody really cares about any of the others, at least not their movie versions.
Okay, I think I've given enough examples. Can you come up with a few?