No, the point of NEXT is to entice customers to upgrade sooner (same with Edge and Jump). Thats where they make their money. They are assuming that most people won't care enough about what they've paid and will be fine trading in their device for the latest and greatest. People who keep their phone for the full 24 months will be the exception, not the norm.
But that has nothing at all to do with the value of the plan.
Stupid people will be stupid no matter what plan they choose.
Next might encourage bad choices but they are still choices.
The plan itself can be a very good deal if you use it responsibly.