It must be technically possible to prevent a drone from flying below a certain altitude. Probably one of the many features that will be added to drones in the coming years.
Perhaps this is possible with a software update, but it doesn't fix the standards to which the drone was mechanically constructed.
Other commercial flying objects are rigorously safety tested for their ability to remain in the air despite different mechanical failures. Without the same standards applied to drones, we are likely to continue to see near-misses or full accidents happen. (Note: I'm not weighing in for or against drone regulation)