There are two aspects. "Charge" and "costs/who pays". When someone can start a Kia with a USB cable, the owner pays for that. Kia may have a fee for replacing something, but that doesn't factor in the calculus of "there's a reason these people are buying our product, and we assess they will continue to do so."
Note that Kia offered a maximum of $6,125/$3,375 for totaled/damaged vehicles.
The previous formula:
"You take the population of vehicles in the field (A) and multiple it by the probable rate of failure (B), then multiply the result by the average cost of an out-of-court settlement (C).
A times B times C equals X. This is what it will cost if we don't initiate a recall.
If X is greater than the cost of a recall, we recall the cars and no one gets hurt.
If X is less than the cost of a recall, then we don't recall."