Verse 34 says "Verily I say unto you, This generation shall not pass, till all these things be fulfilled."
Since you are sure that all of Matthew 24 is in reference to the second coming of Christ, then where are these over 2000 year old people?
The generation that Jesus was referencing was not the generation that included the disciples, otherwise, the second coming would have happened already. He was referencing the generation that would be alive when all these events take place ... sometime in the future.
Perhaps if you explain how Matt. 24:29-31 was fulfilled in the destruction of Jerusalem in 70 AD, I could understand where you are coming from.