Part of me wonders if this is deliberate. No graphics drivers that are useful, no games. No games, no Linux desktop.
Why? AMD has no stake or interest in what OS you game on, they're just looking to sell their hardware. They get no benefit from enabling or pushing a migration to Linux unless they can steal customers from nVidia/Intel that way, which seems highly unlikely. You don't need a conspiracy to explain why companies don't do things that don't benefit them.