What kind of relationship do the Hadleys have with their children?

The Hadleys' relationship with their children is distant, to say the least. They live in a separate world from their offspring, who spend all their time in the nursery watching scenes of nature red in tooth and claw thanks to the wonders of modern technology. George and Lydia live in what we might call the real world, while their kids are immersed in a world of virtual reality with its own rules, norms, and standards. Between these two competing worlds there can be no final reconciliation. They are in direct competition with each other, just like the animals out on the veldt. Indeed, one might argue that the scenes of bloody carnage played out on the veldt represent in extreme terms the state of the relationship between the Hadleys and their children. Technology has not simply undermined their authority as parents; it's driven a fatal wedge between themselves and their children, turning them from parents into prey.

George and Lydia Hadley both have strained relationships with their children due to their differing parenting methods and the futuristic nursery. Although they both love their children, there is a lack of reciprocity on the other end. This is brought to the brutal extreme as the children watch their parents get eaten by the lions they fantasized while in the nursery.
The HappyLife Home, despite its technological advances, diminishes the human aspect of community and familial relationships. This can be seen as a critique of the modern advancements in technology, which simultaneously makes life more convenient for the consumer yet deprioritizes relationships in favor of an alternate reality. Peter and Wendy become more dependent on the nursery than their own parents, who genuinely care for them. While this causes concern for the parents, they weren't able to shut down the nursery permanently. It was their indecisiveness to confront the relational strife in the family that led to their death.