I think that people tend to interpret this parable in a personal, and fearful kind of way. I know I used to think along those lines: "Oh no, I may be that unfruitful tree; so I'd better watch out!" If such interpretations encourage anyone to be a better human, I suppose that's to the good.

But this is, after all, from our good harm-reduction Doctor Jesus. Not from some kind of divine forced-labor taskmaster.

What, then, is this referring to? To the people (and leaders) of Israel. The fig tree and the vineyard are standard prophetic metaphors for Israel; there is no doubt that Jesus' hearers understood him as referring precisely to their nation and its rulers.

Why does Jesus curse that fig tree later on, when he comes to the Temple? That was not some ill-tempered personal snit about wanting a fig! When he tells parables there about the workers in charge of the vineyard, that they haven't been paying the Owner His due... The High Priest and his supporters know this is about them; and they don't like it!

Does it do us any good to think about the sad state of 1st Century Israel and her religion?

Well, yes, that people are our example-- of being called to serve God, but misunderstanding what He wants of us. "The Jews" of the gospels-- stand for us! They mistake their religion in the same ways that Christians, since then, habitually mistake our own.

And the present day Society of Friends:

Do we 'use up the ground' where God intended us to live and bear fruit? Does the contemporary Society of Friends, that is, sit at the entrance to God's Kingdom, so that neither we nor anyone else are entering through our gates?

How, except by God's help, could we ever hope to rectify such a state of affairs?