My guess would be that a majority of people don't know what UFO stands for, or even if they do, don't think about it. Most of the time you hear about UFOs is in pop culture referencing aliens, or the conspiracy guys equating crafts they can't identify as alien UFOs, so it's really not that hard to see why people jump to alien when they hear it.
My guess would be that a majority of people don't know what UFO stands for, or even if they do, don't think about it. Most of the time you hear about UFOs is in pop culture referencing aliens, or the conspiracy guys equating crafts they can't identify as alien UFOs, so it's really not that hard to see why people jump to alien when they hear it.