Let's see....small truck market is shrinking because nobody (not a significant number of buyers) wants a tiny truck. The Ranger's cheap and small...and sales are dropping. Bring in an old-technology Chinese small truck and it will be no better, but the Ranger has 3,000 dealers with a known history.
New vs used is becoming a tougher and tougher thing since late model used vehicles today are of a higher quality than NEW vehicles of just 20 years ago. So if you can get a used 50,000-mile F150 for the price of a new little Chinese truck, which do you think the market will prefer? And Kia sells a few hundred thousand vehicles because they're decent products for their price...they're competing with NEW cars more than used ones.
Imagine a well-equipped 11,000-mile Ford F150 for $9,000 (I just found it on cars.com). Do you really think a truck buyer would choose a new truck the size of a Ranger for the price of a gently used full-sized pickup? As proof...Isuzu sells only a few hundred I-Series pickups each month at the low prices they have and they carry a 10-year warranty. Price isn't everything.