I'm not so sure anymore that there is such a thing as a Goldilocks planet. Liquid water apparently can exist in many more contexts than was previously thought, and life can exist in many more places than previously thought.
It's not like humanity will ever find any other planet we'll be able to live on. I think that, to some extent, sci-fi authors have done the world a disservice - they've made too many people believe that finding another home for humanity is a fairly simple matter, so we can trash the Earth and just go find another one out there somewhere.
And that's what happens when you write speculative fiction in the absence of hard data. Until only about 25 years ago, extrasolar planets were strictly theoretical, and it was broadly assumed that if we started finding other systems, they would be generally similar to ours: orderly, with the rocky Earth-likes close in and the gas giants far out. Which, using the
principle of mediocrity, wasn't an unreasonable assumption to make. Now we know that planets are in all sorts of weird orbits, around all sorts of stars, but that's not the fault of the SF writers. And some of them did assume terraforming marginally habitable worlds (and even uninhabitable ones), or a ubiquity of intelligences on worlds utterly hostile to Terrestrial life.
If there's a problem with public expectations derived from fictional worlds, it's with those who assume that fiction necessarily maps reality, and with an education system that relies on cramming data rather than critical thinking. It's not with the creators of the fiction.
As far as defining Goldilocks zones, I think we need to start talking about that in terms of different degrees of 'just right', and without sharp lines between them. So a Class I Goldilocks zone is suitable to the development of microbial and extremely simple multicellular life, but unlikely to be able to support anything more complex. A Class II zone might support plants and simple animals, but lack anything that pushes evolution forward -- a good environment, but too stable. And a Class III zone is stable over the long term but variable within limits over the short term, permitting complex life to arise and challenging enough that natural evolution continues to progress rather than finds a stopping point. Or something like that.