“Users don’t care about version numbers.”
I did telephone tech support for a year or so, and I wish I had a nickel for every user who said something like “I’m having trouble with my Windows 97.” Users don’t care about anything that isn’t directly connected to the task they’re trying to accomplish. Long, complicated version numbers at least force people to look them up instead of guessing.
Microsoft doesn’t have a strategy of using dates in product names; they have a strategy of isolating the marketing department’s pointless, random name-changes (NT, 2000, XP, Vista) from the engineering version numbers.
If you want dates in a versioning scheme, why not just plain-old dates? Why encode them in some way that makes them harder to read?