I'm in the industry and like others have said, they fill a void in the car market. Not everyone can afford a Corolla, Mazda 3 or some swanky Audi or Merc.
Even from a parents point of view, a brand new vehicle for their child's first car with warranty that is cheaper than a 8yr old corolla makes it a no brainer to the untrained eye.
We all seem forgot at how bad Hyundai and even Mitsubishi were in the early 90s to where they are now is chalk and cheese. I would highly recommend a Kia as an alternative to a Toyota.
Longevity, reliability, and availability of parts is the only real unknown.