Martin's a pulp writer, not a hack writer. He's been around the traps for decades working in TV and niche genre stuff like Wild Cards.
On his day he can write more high-falutin' stuff, like the southern Gothic of Fevre Dream.
His books are full of "grimdark" exploitation, torture and sex, and thinly drawn psychopath antagonists, but that's a norm in modern fantasy writing, or even popular fiction more generally.
Not going to defend him too strenuously though, because after the first few books which hung together beautifully, his series now really lacks story discipline.
