George had reason to be hurt. Granted, until maybe the White Album sessions George was not as good of a songwriter as John and Paul. 1968 and thereafter, I think his songs were every bit as good. The thing that George might have forgotten when he said this was that John was Paul's songwriting partner. George was Paul's lead guitarist as Paul was George's bass player. Obviously, there are exceptions (note: the guitar solo on George's "Taxman").
It would have been nice to see George and Paul write. It should have happened maybe in the late '70s. Paul would have been smart to do so at that time, before John was killed. Now that both John and George are dead, it is sad, that Paul can't go back and do things differently.
We also must remember that 1987/8 was a renewal time for Paul. If you go back and look at interviews and so forth that Paul did around this time, he was starting a new phase.