This question already has an answer here:
Think of some famous outside-of-the-solar-system planets from say, Star Wars. Tatooine. Hoth.
They all have something in common: No matter where you land, the landscape is pretty much the same: on Tatooine it is a desert, possibly with some rocks; On Hoth it is all a frozen wasteland, with almost nightly blizards. It doesn't matter if you land on the pole or the equator, it is the same. However, on planet earth, we have locations where we can film all of thse planets, because of the diversity this planet.
Is it even possible to have such vast climatic zones, or is it just people being too lazy to create more ecosystems into their fictional worlds?