It is a matter of personal taste and cost but can vary widely around the country.
In my area nearly everything is textured ceilings and walls, but used to be just ceilings. A few ceilings were done in patterns in the past (I've seen nothing recently) but most were popcorn of some type, sprayed on instead of being trowelled.
Cost is a factor - the art of producing a smooth wall is dying out in the drywall industry. It is difficult and time consuming to make a smooth wall, and even the most perfect job will still have some drywall joints raised higher than the surrounding surface. The texture hides these imperfections and is quick and cheap to apply.
Personally, I dislike wall texture, but like the ceiling patterned appearance. As has been pointed out, texture is difficult to match when repairs are made.