The book also has a sex scene featuring (spoiler, I guess) a 15-year-old girl. It's probably possible to write something like that in a way that isn't gross, but Stephenson definitely didn't pull it off.
I like Stephenson, he's written some great stuff, but even ignoring that scene, Snow Crash is IMO just a bad book to read once you're out of high school.
It is kind of gross, but so are many things in many books, including in that one (eg all of the disembowelings)
For me it is less problematic than it could have been, because: YT is shown to be naive, reckless and impulsive, and Raven (is that his name? I think so) is an awful person just in general. The author is in no way implying that sex for those two is a good idea, in any way. It's just a thing that happened in the book.
It's also not a sexy scene, so it's not written to be titilating (IMO), and it's short and it does ~something for the plot.
Stephenson at the time Snow Crash was published could write brilliant sentences, so he took ten thousand of them and strung them together into a novel. He matured a lot after that, although I think it took writing the Baroque Cycle to work through his syntax obsessions.