Family has its pros and cons in Home Alone. Pros? They provide the joys of togetherness and assuage one's solitude. Cons? They might act like jerks, devour a cheese pizza that had been set aside for you, and say things like, "I wouldn't let you sleep in my room if you were growing on my ass!"
Overall, though, the pros outweigh the cons. While Kevin thinks he wants his family to vanish, he actually loves them, and he ends up asking a guy playing Santa to bring them back. When they come back, it's a "reunited, and it feels so good" moment.
At the beginning of the movie, Kevin's a bit of a brat and his family is largely right to be irritated with him. Throughout the course of the movie, Kevin earns his right to have them come back, as he grows more self-sufficient and capable of dealing with family life in a non-bratty fashion.
Kevin's family ignores and insults him and he's right to be angry with them and wish for them to disappear. The fact that he manages to survive so well on his own shows that they were holding him back.
Kevin's parents don't intentionally abandon him, but they're forgetful enough to completely lose track of him on the day of their flight to France. This gives Kevin's mom a major case of guilt—she's worried that she's a terrible parent. But Kevin, not realizing that he's been inadvertently abandoned (he thinks he made his family disappear by wishing), enjoys the experience—at first.
Soon, he wants to see his parents again, valuing their protection and love. Kevin's mom makes up for the miscount, which led to Kevin's abandonment (and wasn't her fault, by the way) by strenuously journeying back to him and doing everything she possibly can to reunite.
Kevin's abandonment isn't anybody's fault. It's caused by numerous factors—a miscount of the kids, a nosy neighbor boy, accidental sleeping-in—and not by the active neglect of his parents and other family members. They shouldn't be blamed.
Kevin's family should definitely be blamed for abandoning him. Who goes to a foreign country without carefully checking to make sure that all of their kids are in the car first? By casually outsourcing the head-count to Kevin's sister, Kevin's parents were more neglectful than they should've been.
In order to survive on his own, Kevin has to metamorphose from the wimpy baby he was at the beginning of the movie—a kid who can't pack his own suitcase—to the kind of energetic hero who can systematically dismantle Harry and Marv with a series of ultra-violent booby traps.
He develops into this Man of the Sword by conquering his fears. He faces off with the furnace in the family's basement, banishing the imaginary terror of it from his mind, and stops running away from Marley, realizing that he's a kindly old guy. These experiences help him fend off Harry and Marv, poetically earning him the right to be with his family again.
Kevin finds courage that always existed inside of him. He just needed the circumstances (abandonment and burglars) to bring it out.
Kevin didn't have any courage at the beginning of the movie. Rather, outside forces (abandonment and burglars) made him develop courage, creating it the way pressure creates a diamond.
In Home Alone, violence isn't a bad thing—it's a cleansing and healing force. Without violence, how would Kevin defeat Harry and Marv? Calling the cops? (Okay, that might actually work).
No, instead Kevin uses comical violence to defeat his enemies. He really takes out the full arsenal: blowtorches, BB guns, swinging paint cans, icy steps, and a strategically placed nail. The violence is a huge part of the movie's comedy: it concentrates a ton of the laughs, and feels fundamentally just, since Marv and Harry are the bad guys and they're trying to attack a little kid who's home alone. It's poetic justice.
The violence in Home Alone is enjoyable and comically relieving. It helps us channel our own impulses towards punishment and aggression in a fun and socially acceptable manner.
The violence in Home Alone sends a bad message to America's children because it teaches you that you can resolve problems through violence and shouldn't just tell an adult when you know burglars are going to try to break into your house.
Home Alone hammers out its "crime doesn't pay" moral pretty aggressively. Neither Harry nor Marv is an admirable Robin Hood criminal: they're a pair of frequently blundering idiots who flood houses by leaving the water on after robbing them. They also seem to be driven solely by greed and avarice—they just want all the riches and cool stuff that's probably stored away in Kevin's house. Simple.
There's no extra layer to their motives, no humanizing factor with these guys. They exist as cartoonish villains to be pummeled and broken in, battered by Kevin's vast array of booby traps, until the cops finally arrest them.
Harry and Marv became criminals because of social circumstances—like, their presumed impoverished childhoods and difficult lives. Criminals are made by society.
Harry and Marv are just cartoon villains who embody greed and destructiveness. There's no deeper layer to their personalities, and we can assume that their criminality is purely innate.
We all know the saying, "Don't judge a book by its cover"—and that couldn't be more useful in Home Alone. Marley is like a book with a cover that appears to be bound in the skin of people he's murdered—but inside it's a cute story about fluffy rabbits. Harry, at first, seems like a book bound in an official government issued cover—but inside he's a sleazy copy of Maxim.
If you made snap judgments with Harry at the beginning of the movie, when he's dressed as a cop, or with Marley, based on how Buzz describes him, you'd be wrong both times. Harry isn't really a cop—he's the exact opposite, a robber. And Marley isn't a serial killer—he's just a friendly neighbor who helps shovel the snow of people's sidewalks, salting them to remove the ice.
Kevin has to learn to distrust this impulse to judge based on first impressions, and this lesson ends up helping him. After all, Marley saves Kevin's life when Harry and Marv finally catch him.
Kevin is wrong to judge Marley based on his appearances. You should get to know someone before you make a judgment on them.
Given the known perils of "stranger danger," Kevin is right to be suspicious of any and everybody—Marley included. His judgments based on appearances are just evidence of a well-honed self-defense mechanism.