Desert planets in scifi wouldn’t actually be inhabitable*- there’s not enough plants to produce the necessary oxygen without other climates and ecosystems on the planet. Then there are a host of other problems as well- giant sandstorms being just one of them. Tatooine, Vulcan, so on and so forth- they absolutely fill science fiction, and show up semi-regularly in fantasy.

The problem isn’t just restricted to desert planets, either- forest planets would suffer gargantuan firestorms caused by higher oxygen levels, ocean planets would have giant storms and unstoppable rogue waves of enormous size, city planets… well, city planets have a LOT of problems. There is, of course, one series that is the most serious offender- Star Wars. Tatooine (desert), Kashykk (forest of giant trees), Hoth (ice), Endor (jungle), Coruscant (city), Alderaan (floating rubble), and so on.

While it presents some advantages- namely making each world more easily memorable, the primary apparent rationale is one of laziness. Not everyone can go to the effort of worldbuilding that Frank Herbert or J. R. R. Tolkien went through, or even to the lesser, but still damn impressive efforts of Brandon Sanderson or Dan Simmons, but even a basic, two or three page document on the ecosystem of the world you’re using can be incredibly useful in fleshing out a world.

*The big exception, of course, is Arrakis, from Frank Herbert’s Dune, but that is because Herbert went to the actual effort to create a functional ecology and climate for the world, including carbon dioxide reclamation and a hydrologic cycle (or lack thereof). It’s actually quite impressive- he spent years on it, putting in levels of work comparable to Tolkien’s on Middle Earth- it’s one of the many reasons they’re compared so often.