Crazyguy,
As a Jew, the account does not surprise me. It reads like something I would expect a Jewish sage to say.
The language and symbolism is almost trite, as the prophets of the Hebrew Scriptures so commonly employ the fig tree as a symbol of adverse judgment upon the faithless that Jesus' own words seem hoary. (Compare Isaiah 34:4; Jeremiah 8:13; 24:1-10; Hosea 2:12 [or 14 in some versions]; and Joel 1:7.) But it isn't a tired usage. It is just very Jewish, and very, how can I say "prophet-y" for lack of a better term.
As such it would not likely be an invention of the later Church, not directly anyway. By the time the Gospels began to be written there was too much of a Gentile influence for Hellenism not to influence the language. They were composed in Greek, after all, though the Jewish world of the Second Temple had not ever completely embraced the Septuagint (to this day, the LXX has little to no influence in Jewry).
That the the fig tree incident occurs in Matthew is significant. It makes sense to see it in Luke 13:6-9 and even in Mark 11:12-14, both heavy with Gentile and Roman influence. But even with traditions like that of Papias aside, Matthew is rich in Semitic idiom and seems bent on establishing Jesus as the Jewish Messiah, fulfilling Jewish hopes both Scriptural and traditional. The language is equally untouched, with some Christian scholars wondering if the final version isn't a translation into Greek from Aramaic.
Whatever the case, that Jesus condemns the Temple leaders and the people of Jerusalem as faithless via withering a fig tree to do so is an illustration Jews understand all too well. The texts from the Tanakh I mentioned above have connections to the First Temple's destruction and the faithlessness of the people that led to the Babylonian diaspora. It isn't far-fetched that Jesus used it to describe how little faith Jerusalem had in him. It is still an honest description of my people's faith in Jesus--practically zilch.
But is this a statement that "the Jewish temple was useless and no longer needed" and thus part of the rhetoric that colors other parts of the New Testament that arose from the competition between Christians and Jews in the Roman world? While the interpretation thus stated colors it this way, I would lean to say "no."
Again the image is highly Jewish, borrowed too closely as to be a product of a community breaking away from its Semitic roots. The "fig tree" is a Hebrew symbol of receiving judgment, like tossing away a fig you didn't like (something all too common in Jerusalem where the fig commonly grew so abundantly). Like any inhabitant of the city that had a plethora of figs to choose from each season, the Hebrew prophets used the fig to symbolize how easy God could dispense with or choose to keep those who serve him.
That isn't clear if you only have the New Testament to read. If not for the Hebrew text, the whole reason for a fig being used can get lost. Why stop at a fig tree out of season regardless of how it looked? Who would want an early fig anyway? Do you like to eat fruit out of season or fruit that is in season? The whole scene is a purposeful action of a Jewish sage, going to a fig tree on purpose. The symbolism and the connection are not meant to be lost.
How quick were any of you to note (or recall) the connection between the fig in the Old Testament or where those texts were? If this is a story describing how God is getting rid of the Jews permanently, then something is wrong. A lot is lost on the Gentile mind.
The Gospels were also completed after (or at least near the end of) the Pauline epistle era. In Paul's letter to the Romans it had already been established even to the Gentile Christians that "the gifts and the calling of God are irrevocable," (Romans 11:29) that God had not and would not treat the Jews as forsaken as a whole or forever.
So the text probably is more an opinion of Jesus of how he viewed Jerusalem, its people, and the Temple leaders. They were worthy of his judgment. They had no faith in him. While all three gospels that report this do seem to play off this to connect these words to the fall of the Second Temple in 70 C.E., this play suggests the words were there to begin with. While the connection with the events of 70 C.E. may not have been immediate by Jesus, in view of Paul's statements it can only be taken that any interpretation that these actions of Jesus implied a rejection of Jewry as a whole were probably quite later, likely far after the original apostolic college had passed on.