Speaking in a recent interview, CD Projekt RED’s Konrad Tomaszkiewicz explains that the studio don't charge for DLC because they see it as an post-release service to their fans. He also talks of the decline of the expansion pack and how DLC's too small to fill the same purpose.
CD Projeckt RED have a history of
updated their games with extensive additions for no monies.: both the
Witcher games received new chapters, graphical updates, and engine
“We consider DLCs as a normal post
sale service, which shouldn’t be priced,” said Tomaszkiewicz, in
an interview with VG24/7, “Back when retail games were dominant, we
had expansion packs. These were really large chunks of content, which
were worth their price.”
In his opinion, it's not that a
developer shouldn't ever charge for a DLC but “if today’s DLCs
offered the same amount of content, they would be worth paying for.”
He also suggested that the studio plan
to continue offering free expansions as “a way of saying 'thank
you'” to those who bough their game.