Could you elaborate, specifically with regards to Neuromancer? I'm not entirely following on how parts of it feel like a parody. Some parts have aged poorly (5 mb of hot ram!) but on the whole I think it holds up better than Snow Crash, even taking into account the intentional parody aspects of Snow Crash. Neuromancer retained a strong sense of being grounded in reality, even in the less than stellar sequels. Not everyone knows a super hacker and lives in a dystopian slum policed by brutal riot squads. In Neuromancer most people live perfectly ordinary lives with perfectly ordinary jobs with perfectly ordinary concerns. The corporate intrigue and rogue AIs are on a level beyond most people.
It's not that anything is specifically ridiculous, it's just that so much of what made the book different has become cliché. The cyber-noir, the aggressively gritty tone, the Japaniana that never builds to more than window-dressing, stuff that through no particular fault of Gibson ends up becoming the hallmarks of boilerplate cyberpunk. Even those parts of it which aren't supposed to be taken entirely seriously- cybernetic sunglasses are
supposed to be a silly affectation, surely?- they've been reproduced so many times with straight-faced un-self-awareness that they still grate a bit. It's not that it's done poorly, it's a classic for a reason, it's just that it's all so...
done.
Snow Crash, I'll grant, shows a degree of wear, because the stuff it's parodying is itself dated, but a lot of that stuff persisted well into the 2000s, so it feels like a slightly-dated book from 2002 rather than 1992. (Although if there's a single respect in which its become markedly became dated, it's that its dystonia is a fundamentally pre-9/11 one, of secular, globalised ultra-commercialism; post-9/11 dystopias have run towards the fascistic.)
Perhaps the difference is simply that
Neuromancer gives a fairly loose sketch of its world, so it's easy to fill in the blanks with whatever cliché you'd expect to find, while
Snow Crash makes a deliberate point of screwing with your expectations and so is required to flesh out the world a bit more fully- it's about half again as long, and it wouldn't surprise me if that extra 50% was world-building. But that's partly what it means to age poorly, to become bent and distorted under the weight of what follows. Often when you go back to some a classic, genre-founding text, you're surprised by the ways in which it departs from the cliché- Robert E. Howard's
Conan stories are far more weird and moody than you'd expect from the pop-cultural image of a "barbarian hero" story- but with
Neuromancer, I found pretty much exactly what I expected to find: a well-written but unremarkable cyberpunk story.