Visible is completely owned by Verizon. Many US “MVNOs” are just businesses created to implement price segmentation (price discrimination) for the 3 mobile networks.
It's not price discrimination. MVNO customers, whether owned by the carrier or not, pay less and get less. In order for it to be price discrimination, it would have to be the same service that direct customers of the carrier receive. And it's simply not.
That is a good point. I guess it is more similar to “product binning”? Or whatever it is called when you go to an amusement park and purchase passes to cut 50% of the way into the line, or 75% of the way into the line, and then 95% of the way into the line for a ride?