If memory serves, Stephenson came out in favor of OSX a couple years after its release

With some googling, I found this, a version of ITBWTCL annotated (by someone else) five years later, including a quote from Stephenson, saying that the essay "is now badly obsolete and probably needs a thorough revision". The quote is quoted in many places, but the only link I turned up for it on his own website was dead (not on the Wayback Machine either).