Stephenson is notoriously bad at endings. People tend to describe them in terms that we're bolding presuming you wouldn't want used to describe anything about you or your work: stunted, abrupt, and under-developed.
At the very end of Snow Crash, we know that Rife has been blown up (yay), Hiro and Y.T. have both survived (yay), and Uncle Enzo and Raven may or may not have critically wounded each other in their fight (not sure if yay applies). Better yet, Y.T. hops a ride home with her mom, indicating that hopefully they're going to patch up their relationship.
If we backtrack a little to not-quite-the-end-of-the-book, when we last see Hiro, he saves all the hackers from Snow Crash and gets in a nice advertising plug for himself in the process. Hopefully his no-money woes will end soon because of this, plus things are looking up in the romance department since it looks like he'll get back together with Juanita, too.
If you've noticed a pattern in this section, it's that there are a lot of ifs and uncertainties. Stephenson has indicated that stuff will probably work out a certain way for his main characters, but he doesn't give us the pleasure of knowing for sure that things will work out. Which is kind of frustrating, but life is like that, too.
The fact that the book ends with so many ifs makes us look at the events in the plot and think…huh…how much of what happened was a result of total chance? Hiro and Y.T. met by chance, and went on to save the world; Y.T. delivered Hiro's doomed pizza on a whim, leading to her connection with the Mafia—which is what got Rife interested in her, which got her kidnapped, which helped her stay alive once kidnapped since she was valuable to Uncle Enzo. There's a weird circular logic in all that.
Maybe the end of Snow Crash wasn't inevitable or written in stone; there were too many unpredictable (ahem, Hiro) players in the game for that. But the fact that stuff worked out so well (for everyone except Rife) indicates that cooperation and communication will go a long way toward fixing stuff, even with chance in the mix.