I keep seeing a lot of justifications for the “Peter Quill forgot he had a passenger” thing that boil down to “No, it’s a totally cool way to illustrate that the character’s an asshole! You know, for character development!” and it’s just like…not really, people.
I mean, yes, that is a way that you can demonstrate a character is a total asshole. (There are also other ways to demonstrate that same thing that doesn’t come off as an “lol fuck you” directed squarely at half your audience, but that’s a different argument.) But the problem with that is that otherwise he doesn’t come off as the sort of asshole who’d do that sort of assholish thing. He’s immature and dysfunctional and venal, yes. But the first time we get any sort of character scene for him, he’s got a black eye from getting into a righteous-anger fight over a dead frog. He’s surrounded by what appears to be a loving family in the throes of grief, from whom he’s summarily kidnapped by what turns out to be a gang of space-pirates.
He spends the rest of the film coming off like the sort of person who’s had to play The Functional One for the crew of the HMS Warp Factor Clusterfuck for over half his life. I don’t know if the repeated comments about eating him were meant to be taken absolutely at face value—there’s an argument to be made for reading them as some seriously fucked-up emotional blackmail rather than a genuine threat—but the dialogue about Yondu killing him if he gets out of line clearly isn’t a joke. Whatever affection or use the pirates have for him, it’s explicitly not enough to keep him safe from them. It’s not exactly an accident that the first instinct we see him showing almost every time there’s trouble is to try to smooth things over.
Rocket starts planning the escape from prison, and what happens? Groot straight-up rips something out of the fucking wall right in front of the guards. Drax engages in some good old ultraviolence. Gamora comes back with a device that was hardwired into somebody’s nervous system without batting an eye. Peter…pays a guy a (judging by other sums mentioned) sizable chunk of money in exchange for the thing he needs. Attempting to beat the dude up and take his stuff never even seems to occur to him.
He tries to talk everybody down when the other inmates are planning to murder Gamora. He tries to talk everybody down when Rocket and Drax start fighting. He’s the one who calls the Nova Corps to warn them instead of just showing up with what looks like an invasion fleet. When Rocket pulls the “I need your prosthetic” thing again, Peter jumps in the middle and shuts it down like he’s apologizing for his racist grandma.
He comes off like a guy who’s had to invest way too much energy, for way too long, into figuring out how everyone can go home happy and nobody needs to die today. Like, how many times has he seen some variation on the psychic arrow vs. Kree soldiers scene play out with Yondu because he couldn’t defuse a situation?
Peter Quill isn’t supposed to be a huge asshole. (That would be Rocket, for those of you playing along at home.) He’s supposed to be a fuck-up who’s figuring out that there can be more to his life than chasing the next thrill, pathologically flouting authority, and dodging his abusive foster-family.