You have to consider the sources of the stories we read. Archaic/classical Greeks were individuals like everybody else and had differing opinions of their gods. Homer, for instance, is notoriously not a fan; you can find later writers complaining about how unflattering his portrayal is. A pious believer in Zeus would have loved and admired him as a benevolent paternal figure who keeps order in the universe. Now, as
@Celebrim explained, classical Greeks had pretty awful views on women and sexual relations (even by the standards of the era), and this pious believer would most likely have seen the myths of Zeus raping and seducing as evidence of him exercising his awesome power. And they would have also have been well aware of the myths of Zeus punishing people for their hubris, so they might have feared him a bit in that sense. But they would not have viewed him as
nasty, and I don't think it would be accurate to say their worship was "purely fear based". The Abrahamic God also metes out punishments and condemns people to Hell, but believers love him far more than they fear him. Same deal. Remember that modern depictions of God as a big man with a white beard in the sky
borrow that image from Zeus.
And Hera, for her part, her perceived nastiness comes from the popularity of from the Iliad (where all the gods are douchebags) and the Heracles myths (which are pretty definitively pro-Zeus). She is a much more positive figure elsewhere, a protector of families, women, and children. The sort of deity a wife might pray to to keep the household functioning while her husband was out committing rape and violence.
