End of the world is already late

With all the discussion of the impending end of the world, at the end of the Mayan long count on 21st December, everyone seems to forget that it is already much too late.

Biblical accounts of the words of Jesus suggest that he predicted the coming of the Kingdom of God within the lifetime of the people who were listening to him.  The various accounts differ in detail, but all of them are now long past their sell-by date.

But let's look at what the bible says.  Was it that everyone there would see the coming of the Kingdom, or was it just some of them as suggested in Mark 9:1 (just before some nonsensical happenings on a mountain).

John 21:23 seems to suggest that it applies to only one man (who happened to be the author of the Gospel of John).  But when it became clear that none of the prophecies had come true, long after the last person in Jesus's audience must have died, the church began its long series of excuses.

2 Peter 3:4 ff shows how all that began.  We get all the 'one day is as a thousand years' argument.  The day will come, unexpected as a thief ... blah blah.

That doesn't really address the issue at all, does it?  'The thief' hasn't come in 2000 years.  I don't believe in 'the thief' any more than I believe in God or Jesus.

Why do Christians not see the absurdity?