BUZZ: I wouldn't let you sleep in my room if you were growing on my ass.
Buzz is a traditional, bullying older brother. Obviously, he's not trying to inspire any affection in Kevin, and he's one of the factors in Kevin's wish for his family to disappear.
KEVIN: I don't wanna sleep with Fuller. You know him, he wets the bed. He'll pee all over me, I know it.
Kevin's extended family doesn't exactly warm his heart either. It's hard for Kevin to sense the real bonds of love that unite them when a flood of his cousin's urine is about to soak him. It's another strike against families in Kevin's book.
KATE: My husband's brother transferred to Paris last summer and both of his kids are still going to school here and I guess he missed the whole family. He's giving us all this trip to Paris for the holidays, so we can be together.
Ironically, in trying to be together for the holidays, by going to Paris, the McCallister family leaves Kevin behind, separating the family.
KEVIN: Everyone in this family hates me!
KATE: Then maybe you should ask Santa for a new family.
KEVIN: I don't want another family. I don't want any family. Families suck!
This is how Kevin starts off in the movie—brattily attacking his family. (To be fair, they have been a little obnoxious). Throughout the course of the movie, he learns to fend for himself without a family, while simultaneously realizing that he wants his family back.
KEVIN: I don't want to see you again for my whole life. And I don't want to see anybody else either.
KATE: I hope you don't mean that. You'd feel pretty sad if you woke up tomorrow morning and you didn't have a family.
KEVIN: No I wouldn't.
KATE: Then say it again. Maybe it will happen.
KEVIN: I hope that I never see any of you jerks again!
Of course, by the time the movie ends, Kevin wants his family back—even though he's learned how to survive on his own. He's not dependent on them, anymore, but he wants to spend time with them because he actually likes them now.
KEVIN: [worried] I made my family disappear.
[He remembers the things his family members said to him.]
KEVIN: [happy] I made my family disappear.
Kevin's family really were acting like jerks—mainly because of the stress of getting ready for their big trip, but also because Buzz and Uncle Frank are jerks, though in a not very serious way. So, we can sympathize with Kevin to a fair degree.
KATE: This is Christmas! The season of perpetual hope! And I don't care if I have to get out on the runway and hitchhike! If it costs me everything I own, if I have to sell my soul to the devil himself, I am going to get home to my son.
We see that Kevin's Mom really cares about him; contrary to what Kevin thinks, his family doesn't really see him as useless dead weight.
KEVIN: This is extremely important. Will you please tell Santa that instead of presents this year, I just want my family back. No toys. Nothing but Peter, Kate, Buzz, Megan, Linnie, and Jeff. And my aunt and my cousins. And if he has time, my Uncle Frank. Okay?
This is the moment when Kevin (speaking to a guy playing Santa) admits that he really does want his family back. It's a crucial moment of dramatic reversal in the development of his character. Ironically, the Santa doesn't know that they've all gone to France, and imagines that they're dead.
MARLEY: Years back, before you and your family moved on the block, I had an argument with my son.
KEVIN: How old is he?
MARLEY: He's grown up. We lost our tempers, and I said I didn't care to see him anymore. He said the same, and we haven't spoken to each other since.
Kevin's only been separated from his family for a few days, but Marley's been estranged from his son for years. It's an example of how damaging this kind of separation and loneliness can be. Yet Kevin is able to help Marley make up with his family, since Kevin has recently learned how valuable family actually is: he can impart that wisdom.
KATE: I'm a bad parent. I'm a bad parent.
GUS: You're not. You know, you're beating yourself up there, you know. This happens. These things happen, you know. Gee, you want to talk about bad parents? Look at us. We're on the road 48, 49 weeks a year. We hardly see our families. You know, Joe, over there. Gosh, you know, he forgets his kids' names half the time. Ziggy over there, he's never even met his kid. Eddy: let's just hope none of them write a book about him.
This is played purely for laughs. It's like Gus's Polka band is Led Zeppelin or something—getting torn up by life on the road and separated from their families.