Other users on NeoGaf have mentioned that this is normal for Rockstar Games since the end of the PS2 era. NeoGaf user ‘fantomena’ has cited a post from a GamesPlanet team member and the listing on GreenManGaming that has the ‘other DRM’ logo on the Grand Theft Auto V page.
Fans are taking to NeoGaf to discuss what appears to be common practice in recent Rockstar titles, the inability to allow Steam integration with retail copies of their games.