As found on the Steam community page
Arrowhead made the deal with Sony to have them handle publishing (customer support, server infrastructure, etc) while Arrowhead gets to focus on developing the game. Part of this deal was a requirement for players to have/use a PSN account.
Arrowheads CEO knew of this requirement at least 6 months prior to release (by his own admission) but bypassed it temporarily to get the game out.
At the same time, Sony as the publisher allowed the game to be sold in regions that don’t support the PSN network; meaning players/customers in those regions are now locked out of the game they’ve purchased. Sony could relax this requirement, even just limited to those that purchased before the requirement was enforced, but so far they have not.
It was Arrowheads decision to disable/not implement the PSN integration, despite knowing well in advance of release it would be required to fulfill their contractual obligations.
It was also Arrowheads decision to partner with Sony, while knowing the terms of that agreement included a requirement to implement PSN integration.
